My husband and I went here for our Anniversary while on a Norwegian Cruise Line about 15 years ago and it really was one of the coolest things we have done on a vacation! Cancun, Mexico- Xcaret Underground River, one of the coolest things you'll ever do!
Fingal’s Cave, Inner Hebrides, Scotland. "Fingal's Cave is a sea cave on the uninhabited island of Staffa, in the Inner Hebrides of Scotland, part of a National Nature Reserve owned by the National Trust for Scotland" via Wikipedia.
Heart Sea Arch, Portugal - Whosoever shall confess that Jesus is the Son of God, God dwelleth in him, and he in God. And we have known and believed the love that God hath to us. God is love; and he that dwelleth in love dwelleth in God, and God in him.