Sikia Cave in Milos, Greece is a hidden gem for adventurous hikers looking to explore the largest sea cave on the island. The trail to the cave is a bit tricky to follow, with some steep sections and rocky terrain, but the payoff is totally worth it. Once you reach the cave, you'll be greeted by a massive entrance and a natural skylight that lets in the perfect amount of sunlight. Plus, you can even take a refreshing swim inside the cave if you're feeling brave! Just make sure to keep an eye out for goats and maybe a sneaky snake along the way.