St Peter's church, Vienna, Austria St. Peter's is thought to occupy the oldest Christian sacred site in Vienna, as a church has stood here since the second half of the 4th century. According to legend, Charlemagne founded a larger church here in 792.
Austria's Green Lake in the Hochschwab Mountains is a hiking trail in the Winter. The snow melts in early Summer and creates a completely clear lake. The Lake has a grassy bottom, complete with underwater trails, park benches and bridges. So cool!