Balduinseck Castle is located in the valley on the L 203 between the towns of Buch and Mastershausen and is freely accessible. The hilltop castle was built in the 14th century by Elector Baldwin of Luxembourg as a stronghold against the Counts of Sponheim, who resided at Kastellaun Castle. When it was built, Baldwin seems to have been particularly inspired by the French donjon type. The castle was never destroyed but fell into ruin from the 18th century. Comprehensive renovation began in 2009 - it was finally completed in 2014, making the site freely accessible again. The 18-meter-high, four-story walls of the residential tower are still well preserved today. Today, Balduinseck Castle is a special highlight for many hikers on stage 20 of the Saar-Hunsrück climb (Mörsdorf-Kastellaun) and the Masdascher Burgherrenweg dream loop (Germany's most beautiful hiking trail 2018).