Burg Altena, situated amidst the heavily wooded hills along the Lenne Valley, was built in about the 12th Century and was the seat of the Counts of Mark.  It was also the site of the world's first youth hostel, which it still has today.

The view of the town of Altena and the Lenne Valley from the upper chamber of the Pulver Turm (Powder Tower) rivals anything offered along the Rhine.