Nothing beats relaxing by the water while you're on vacation. Take a picnic to Lake Batak and then stick around for a peaceful sunset.
This body of water in Rhodopes Mountains comes recommended by travelers, so make a spot for it on your schedule. However, your day doesn't end there. There are loads more options ready for you to check out after Lake Batak. History Museum, Church of Sveti Nedelya, and Ethnological Museum are not far away.