Hallgrímskirkja is a magnificent church that watches over the city, with a design inspired by basalt columns found in Iceland's natural landscapes. The interior features a minimalist design and a colossal pipe organ. An elevator ride to the top of the tower offers 360-degree views of Reykjavík's colorful rooftops and surrounding mountains. Church is free but you do have to pay $15 to go up into the tower. Hours vary by season.