Using the heat from the Earth’s interior to generate electricity is known as the creation of geothermal power, and in the examples featuring 2000-metre boreholes, it’s correctly believed to be a fairly recent development. In some places however, the energy from the hot parts of the Earth’s inner layers can be harvested with little more than a spade.

The area around Larderello¹ in Tuscany’s Cecina valley has an abundance of hot wells (lagoni) and natural steam fountains (sofioni), where the escaping steam leaves the ground under very high pressure at temperatures of over 200°C; making it ideal for power generation.

The gases released here also smell strongly of sulphur, which is why this is known as Valle del Diavolo – “The Devil’s Valley”.

A working geothermal generator (using a steam-powered piston engine) was demonstrated² here as early as 1904, and Larderello actually became the location of the world’s first geothermal power plant all the way back in 1913! Today, over one third of the electricity consumed in Tuscany is produced by local geothermal plants.

The whole countryside around the town is criss-crossed by large insulated pipelines transporting superheated steam from the wells to the power station.

In 2005, nearly 10% of the world’s geothermal electricity was produced in Larderello, but as more, high-tech geothermal power stations have been built around the world, this proportion has shrunk dramatically.

You can take a guided tour if you’re in the area, of which one of the highlights is a steam outlet that the tour guide opens with a remote control to create a deafeningly loud, and very impressive-looking column of steam:

You can read more about Geothermal power at Wikipedia.

Where the North Sea meets the Baltic Sea¹, there’s Grenen²; a spectacularly unspectacular sandbank at the northern end of Jutland, the continental part of Denmark.

The form and position of the sandbank’s tip can vary considerably over short periods of time, when waves³ and currents remove or deposit sand.

On the long term however, Grenen is growing by almost a kilometre (roughly half a mile) per century, slowly extending towards the north east. A closer look at the aerial picture shows distinct stripes in the landscape: successive layers of silt and sand that have accumulated over time.

Of great importance is the 46m (150ft) high lighthouse close to the tip.

Despite the increasing use of advanced navigational systems, the lighthouse is still crucial to the safe passage of more than 100,000 ships that pass Grenen every year.

Due to its prominent position in between seas, the location has also been of great military interest for many years. What remains today are several very sturdy concrete fortifications and artillery positions built by the Germans during World War II.

These structures are part of the huge Atlantic Wall project, a chain of coastal defences built by the German Third Reich that runs from southern France to the northern end of Norway. The Wall was never completely finished, and save its French parts never saw much use.

A little further to the south lies the “Tilsandede Kirke“, or “silted up church“. Built around the 12th century, it was the region’s most important church.

However, beginning in the 16th century, it had to regularly be dug out of the sand that amassed around it, and was finally given up in 1795. Its main building was torn down to reuse the building materials, while the church’s tower remains as a historical site.

Grenen today is a popular leisure destination⁴ and a nature reserve, protecting the region’s distinct vegetation including several kinds of orchids. It is also a popular site for bird spotters looking for passing eagles, ospreys, cranes, storks and ernes, amongst many others.

New writer: Cédric Cédric lives in Germany where he works for the science and education department of one of Germany’s regional public radio and TV stations. He has a life-long project to see the world, especially by train.

The invention of the road was probably rather quickly followed by the idea of the bridge, simply because wet feet are pretty annoying when travelling. And so, over the course of thousands of years, many, many bridges were built. The beginnings were humble, and none of the very early wooden constructions survive.

However, with the invention of the arch over three thousand years ago, things got moving (and spanning). At first, arches were crude, but nevertheless the results proved to be solid; the three Arkadiko Bridges, built by Mycenaean Greeks at the end of the Bronze Age in around 1200 BC, are still with us – and one is even still in usable shape today.

In even better shape are the Tarr Steps, a “clapper bridge” in southern England, which was probably built around 1000 BC. The Tarr Steps are made of raw stone slabs weighing several tons apiece; some of which have occasionally been carried up to 50 m downstream during floods, but they’ve always been placed back on their piers afterwards.

With the rise and expansion of the Roman Empire came architects and engineers, who had more modern building materials such as cement and concrete at their disposal. The Romans built smoothly paved roads, palaces, temples and thermal baths¹ all over the Empire, as well as the first truly large-scale bridges for roads and water. Many of these Roman viaducts and aqueducts are still in amazingly good shape today.

One of the most famous Roman aqueducts is the two thousand year old Pont du Gard, a three level, 50 metre (165 ft) high structure that forms part of a water conduit over 40km (25 miles) long which carried water to the Roman town of Nemausus, today’s Nîmes.

About the same age is the Pont Saint-Martin, spanning the river Lys with an arch of over 30m (100 ft) – one of the widest arches of the time². Amazingly it’s still in day-to-day use.

After the Romans had left (or were kicked out of) most of Europe by around AD 600, large-scale bridge building hit a bit of a recession. Big bridges for big roads were no longer needed to facilitate the Empire’s infantry deployments, and the big workforces (i.e., lots of slaves) weren’t that readily available any more.

Wet feet were still widely out of fashion though, and as traffic increased, the local Europeans eventually built their own big bridges. Nearly 900 years old is Avignon’s Pont Saint-Bénezet, better known as the Pont d’Avignon.

Over the course of 500 years, the Pont d’Avignon repeatedly collapsed due to heavy floods and shoddy repairs, and it was eventually abandoned in 1668. Today, less than a fifth of its original length remains.

In some other places, wet feet were so unpopular that bridge builders just kept on building. The 800-year-old Swarkestone Bridge in England’s Midlands not only crosses the Trent, but also adjacent swamp lands.

At over a kilometre long, the Swarkestone Bridge is England’s longest stone bridge, and in daily use by hundreds of drivers. However, its builders never imagined their work to be so heavily used; after nearly eight centuries of stability, the Swarkestone Bridge and Causeway is in dire need of repairs.

With constant population growth, traffic increased everywhere. Local traffic in the emerging metropolises proved to be especially annoying. In Paris, this lead to Henry III (the French one) ordering the construction of a new bridge across the Seine river in 1578. Finished in 1607, it became the Pont Neuf, or “New Bridge”.

Ironically, the Pont Neuf is now Paris’ oldest surviving bridge, and it’s surviving very well. Open to normal road traffic in the heart of Paris, the then nearly 400-year-old construction had to bear a load of 10,000 cars a day until the introduction of new traffic routes in 2004. It’s much quieter today, but still crossed by hundreds of drivers every day.

Bridges have always been more than a mere Thing To Cross Things. A big bridge was also a display of power and technological prowess. Bridges not only had to be useful, but also had to intimidate enemies and impress friends. Many bridges in big cities are much more elaborately built than would be dictated by mere necessity, be it the impressive Tower Bridge³ in London, or Rialto Bridge in Venice.

A new bridge’s look is still of great importance nowadays, despite a certain lack of enemies in need of intimidation. They please locals, appeal to tourists and serve as interesting landmarks. New bridges are often built according to beautiful and unique designs despite almost always being more expensive than is strictly required.

Modern building materials and techniques allow for much greater freedom in forms and shapes, with often stunning results. Over the last decades, some truly beautiful, big, delicate, or simply weird bridges have been built, such as the Gateshead Millennium Bridge which implements a novel lift bridge concept, or the previously featured Wasserstraßenkreuz Magdeburg, which allows a shipping canal to cross a river.

Today, bridges routinely span more than a kilometre without touching ground. They brave storms and earthquakes, relying not on divine protection but on engineers’ ingenuity. However, modern industrial materials, despite their incredible properties, have a significantly lower life expectancy than bare rock. A thousand years from now, there probably won’t be too many bridges left of those built over the last few decades – while some roman or mediaeval constructions have a fair chance of still being around to amaze and impress our descendants.

We adore bridges here at Google Sightseeing, and to prove it, our Bridges category features nearly 100 of the world’s most fascinating bridges.