Opal Lake is a former granite quarry; after the quarry closed in 1970, the area filled with water and became the deep and impressive Opal Lake. Today, it is a beautiful natural area with excellent hiking trails and a fantastic view of the Baltic Sea. Opal Lake is located at the foot of Hammerknuden and is a former quarry lake that now boasts crystal-clear water surrounded by steep cliffs. The clear, blue water surrounded by cliffs gives the place a calm and distinctive atmosphere. The spot is perfect for a peaceful hike, and for the adventurous, there are cliffs from which to jump into the water.

Depth: Approx. 10 meters

Interesting facts: Former granite quarry from the 19th and 20th centuries, now filled with crystal-clear water surrounded by steep cliffs.

Experience: Great place for hiking, with cliff jumping opportunities for the adventurous.

Ruby Lake is one of Bornholm's hidden gems. Ruby Lake is a former coal mine south of Hasle. Between 1942 and 1948, over 30,000 tons of lignite were extracted from the area, which is now filled with water and bears the poetic name Ruby Lake. Today, the quarry lake is surrounded by wild bushes and trees, making it an ideal destination for a peaceful picnic or a swim. The water has a characteristic ruby-red shimmer in sunlight, making it unique and special. You can also fish for pike without needing a fishing license.

Depth: Approx. 18 meters

Interesting facts: Former coal mine from World War II with a characteristic ruby-red shimmer in sunlight.

Experience: Ideal spot for picnics, fishing without a license, and relaxation.

Hammerknuden Lake is Bornholm's largest lake and is situated in a rift valley on Hammerknuden near Sandvig. The lake offers a beautiful hike around its perimeter, where one side provides a paved route, while the other features more uneven terrain. Hammerknuden Lake is also popular among anglers, but remember to bring a fishing license. From the area, you can enjoy a fantastic view of the Baltic Sea and the rugged coastline that characterizes the region.

Depth: Approx. 13 meters

Interesting facts: Formed in a rift valley during the Ice Age, featuring a mix of paved routes and uneven terrain.

Experience: Popular spot for hiking and fishing (requires a fishing license), with beautiful views of the Baltic Sea.

Emerald Lake is located in Sorthat near Hasle. Today, the lake is known for its clear, greenish water and tranquil atmosphere. Emerald Lake boasts a varied fish population, including roach, tench, perch, and large pike. The area also offers a lovely sandy beach and scenic trails in Hasle Klinkerskov forest. The lake is nestled in a peaceful forest area, offering an idyllic atmosphere for both hiking and relaxation. This lake is part of Bornholm's largest bog area, Bastemose.

Depth: Approx. 5 meters

Interesting facts: Formed after clay extraction in the early 1900s, known for its clear, greenish water.

Experience: Ideal for fishing and relaxing by the beach, surrounded by scenic trails in Hasle Klinkerskov forest.

Sapphire Lake is located in Sorthat, south of Hasle. Today, Sapphire Lake is a perfect spot for freshwater fishing, requiring no fishing license, where both children and adults can enjoy the many small fish in its clear waters. Sapphire Lake is a beautiful and tranquil lake known for its clear, blue water that shimmers like a sapphire in the sunlight. The lake is idyllically situated amidst a forest, offering pleasant picnic areas and excellent opportunities for relaxing walks. Its secluded location makes it a quiet and peaceful place to relax.

Depth: Approx. 6 meters

Interesting facts: Former clay pit, known for its clear, blue water that sparkles like a sapphire.

Experience: Ideal for fishing without a license, picnics, and relaxing walks in peaceful surroundings.