The four storey Hazelslack Tower is a few yards off the B5282 near the village of Storth, West of Beetham and South of Kendal. The tower that survives is today interpreted as a pele tower. The only reminders of the former hall block are the marks of the eaves on the walls of the tower. A huge fireplace can still be seen where the hall joined the tower. The tower was most probably built during the late 14th century, and was certainly in ruin by the 17th century. The many windows mostly remain in situ, with their sandstone surrounds mostly intact. The tower was reputedly built by Lucy, Margaret and Katherine de Throeng. Together with their brother, Thomas de Throeng, they owned one quarter of the Barony of Kendal. The tower was built in conjunction with a tower at Dallam, now demolished and replaced with the great hall, and also Arnside Tower.
Its design is very similar to other towers nearby, the ruined Arnside Tower and Wraysholme Tower. It may also be that the tower at Hazelslack was incomplete. Maybe the threat of Scottish raids had subsided by the time the building was underway. The tower is easily visible from the road, and forms an integral part of the Limestone Link walk from Arnside to Kirkby Lonsdale, passing through some great limestone countryside.