Pantheon

Pantheon is Greek for "honour all Gods", this temple was built to honour Roman Pagan Gods but is now better known as being the best preserved Ancient Roman monument. 

It is a very impressive structure. The exact date of the construction is unknown. The building has an aura of mystery about it, people wander in and out freely but not much is said about the history of the building and what it is for. The architecture is amazing. A hole in the roof lets light in, and occasionally, rain. The interior of the building is circular, with these amazing mosaics and marble features everywhere. Right around the corner from the Trevi Fountain, I would definitely label it as a must see when in Roma.