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The most interesting building I've ever seen has got to be the Sagrada Família Church in Barcelona. An unfinished masterpiece designed by Catalan architect Antoni Gaudí, the church is already 136 years in the making today. Groundbreaking began in 1882, and it not expected to be finished until 2026, 100 years after Gaudi's death.

One of the most polarizing architectural buildings in the world, it has been described as "greatest piece of creative architecture" and a "marvel of technical perfection", on one hand, while also being called "one of the most hideous buildings in the world" and "one of the strangest-looking serious buildings in the world" by critics.

What I find interesting about the building is its uniqueness. Classified as gothic architecture, it has a unique design compared to all the Roman Catholic churches I've seen. The whimsical, organic, and almost alive character of the building is not something you will find on other churches. 

I've never been to a structure that has evoked so many emotions from me, as well. Being there made me feel a combination of awe, confusion, marvel, and at times, a little bit unsure over some of the pieces I was seeing. 

Another interesting aspect of the building is the symbolism behind every little detail of the construction. From the positioning of the different facades to the decision to use strange-looking sculptures, and the number of spires to be built. Touring the site was like getting a quick lesson on the tenets of Catholicism, too.

I would love to go back to Barcelona and visit the Sagrada Família Church, again. It's not only one of the most interesting buildings I've ever seen, being there was also an amazing experience that I would repeat in a heartbeat. 

Source:

Sagrada Família. https://en.wikipedia.org/wiki/Sagrada_Família

The most impressive museum for me is the Smithsonian National Air and Space Steven F. Udvar-Hazy Center Museum outside Washington, D.C., the capital of the United States.

This building is an addition to the actual National Air and Space Museum in the city. But because the collections of aircraft have not fit inside the original building, then a hangar was built which could accommodate various historic aircraft.

Airplanes displayed include:

- Enola Gay, Boeing B-29 Superfortress bombers that dropped the first atomic bomb on Hiroshima at the end of the Second World War;

- Space Shuttle Discovery, which runs more space missions than any other space shuttle, and which also carries the Hubble space telescope;

- Lockheed SR-71 supersonic surveillance aircraft, nicknamed "Blackbird", which was often used by the United States Air Force during the Cold War;

- Supersonic Concorde aircraft former Air France airline that used to run transatlantic flights between continental Europe and North America.

- Various types of Japanese and German warplanes are relics of the Second World War which are the last aircraft of their kind;

- The Dassault Falcon 20 jet aircraft used by FedEx's courier company for its inaugural flight;

- Gossamer Albatross, a human-powered airplane that successfully crossed the English Channel in 1979;