The remains of the early mediaeval castle are currently the most interesting sightseeing destinations in the Bug river valley.
On the Castle Hill ( 189 m above the sea level) there are still the remainders of stone towers, ramparts and moats and the ruins of the Saint Alexander Newski chapel built in 1865 to commemorate the rescue of Tsar Alexander II. On bottom of the castle, at the base of old rampart, are the ruins of Saint Nicolas church, destroyed in 1915. The ruins on the Castle Hill remind the sightseer of interesting events in the history of Mielnik.