Sometimes buildings, whether they’re old or new, hide their own secrets. We can be walking by them every day and not know about the unique features of this or that house. However, learning about them is actually fascinating, because these hidden details often tell the most interesting stories.

We at Enlighten love urban tourism and are always happy to learn about the hidden features of urban architecture — that’s why we have compiled the most impressive objects for you in this article.

13. Horse Guards Clock, London, UK

Jonathan Cardy / Wikipedia

Attentive tourists may notice that there is some strange dark spot that looks like either a stone defect or a fungus on the tower clock of the Horse Guards Clock in London. It is located right at the 2 o’clock mark.

The black mark on the clock face is not dirt or mold. This dark spot marks the time of the execution of King Charles I, near this place on January 30, 1649, at 2 p.m.

12. Housing unit, Marseille, France

Iantomferry / Wikipedia

The apartment building in Marseille, which was designed by Le Corbusier and built in 1952, was supposed to begin the active construction of the same type of buildings throughout France. It might look like a normal block of apartments to a person who is not well-versed in architecture, but it’s not quite like that.

Le Corbusier came up with a new concept for building blocks of apartments with a perfect (in his opinion) correlation between the individual and the collective. The concept included the theory that there would be no necessity for a resident of the building to have to leave the building in order to satisfy any of their needs — all public services, as well as shops and restaurants, were located inside. Moreover, the apartment building has a hotel and a school inside.

11. Riga Central Market

Diego Delso / Wikipedia

Riga Central Market is a large roofed market found in Riga, Latvia. It occupies a huge area of 7.23 hectares and is made up of 5 pavilions, which are the main attraction. The thing is that those pavilions used to be German Zeppelin hangars that were repurposed into a market.

10. “Witch House” of Odessa, Ukraine

Yuriy Kvach / Wikipedia

This building, located in Odessa, is also called “The Wall-House” and “The Flat House” because it may seem that it only consists of a façade from a certain angle.

Much of the history about the building has been lost to time. According to one popular theory, the flat appearance was created to save on labor costs by connecting 2 lateral walls. Another explanation is that there wasn’t enough land to build a traditional building.

9. The “Ideal Palace,” Hauterives, France

Benoît Prieur / Wikipedia

It’s hard to believe but this building was constructed by one person — a postman named Ferdinand Cheval, who had neither an architecture degree, nor money for construction materials. He had been collecting sideroad stones from 1879 until 1912 (33 years in total) while he was delivering mail.

It took him years to construct this bizarre building, where it’s impossible to point out just one architectural style. Nevertheless, after many years, Ferdinand even got recognition from Pablo Picasso himself.

8. Bahrain World Trade Center, Manama, Bahrain

GN-z11 / Wikipedia

This skyscraper that was built in Bahrain in 2008 got an award for its nature saving design. The bridges connecting the twin-towers have built-in wind generators. The sail-shaped building is designed so that the wind passes through the turbines at maximum speed. Wind generators provide up to 15% of the skyscraper’s yearly total energy consumption.

7. Residential block Marzahn-Hesseldorf, Berlin, Germany

The residents of the Berlin district of Marzahn used a non-trivial approach to restoring the panel block of flats left from GDR (German Democratic Republic) times. The small district of gloomy high-rise buildings was turned into a fashionable district with the help of a little paint. Balconies, fretwork, marble, and other beautiful details are all murals, which is, by the way, the largest in Europe.

Thanks to this, this sleeping district started to attract tourists. Those who don’t know the secret will never guess that all this beauty is actually art.

6. The smallest house in Paris, France

The building that is as wide as a queen-size mattress used to be a shoemaker’s workshop. Today it’s a residence with a separate entrance.

5. Mikael Agricola Church, Helsinki, Finland

Ranerana / Wikipedia

Mikael Agricola Church was built in Helsinki, Finland in 1935 and has one interesting detail — the nearly 100 foot spike that can be retracted if necessary. During the war, air raids were quite frequent here and the government didn’t want the spike to become a reference point for enemy bombers.

4. “Villa Rose,” Vaud, Switzerland

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Although Switzerland didn’t participate in the Second World War, it maintained armed neutrality and was ready for an attack at any moment. They elected the military government, and built “The Toblerone line,” which is an anti-tank defense line made of concrete blocks, as well as other fortifications, including the fortress “Villa Rose.”

It looks like an ordinary house from the road, but if you look closer you’ll see that the windows in the house are drawn on. In the ’40s, this fortress always had a platoon of soldiers ready to attack, as well as artillery guns in it.

3. Taipei 101, Taiwan

Peter Schlüter / WikipediaSomeformofhuman / Wikipedia

It’s well-known that due to strong winds, skyscrapers deviate from their axis: the residents of the upper floors can even feel something like seasickness. In order to minimize this effect and make these types of buildings more stable, a special inertial damper is used — it is a huge pendulum that is suspended in a special shaft closer to the top of the building.

The Taiwanese skyscraper, Taipei 101, has the largest damper in the world, which is a huge sphere that weighs 660 tons.

2. Hundertwasserhaus, Vienna, Austria