Camping & Jachthaven De Mars is a family-run campsite and marina situated within the 400-hectare recreation area of Rhederlaag, near the village of Lathum in the province of Gelderland.

The facility sits in open connection with the IJssel river, with extensive water surfaces surrounding the grounds.

The site comprises both a campground and two marina basins — the Oosthaven to the east, which includes berths for visiting boats, and the Westhaven.

It serves as an access point to the waterways of Rhederlaag, making it a base for water recreation enthusiasts as well as campers seeking nature and quiet in this riverside setting.