At the all-inclusive Majestic Colonial in Punta Cana, Dominican Republic, you have access to the beach and the 1,300-foot-long pool, plus meals and drinks at the eight restaurants and nine bars for only $150 per person, per night, (From: 10 Best Budget Friendly All-Inclusive Resorts)
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!