We leave the parking lot at the fort to the castle Cantecroy. This castle was originally one of the oldest castles in the province of Antwerp and may have originated from a Frankish allodium. The oldest parts of the current castle date back to the 13th and 14th centuries. There is also an old Gothic farm and a pillory of the local court.
We cross the railway bridge and past the cemetery we arrive in the Klein Zwitserland (little Switserand) nature reserve. The site was a railway junction from 1878 to 1970 and owes its name to the raised railway verges. Since 1996 Natuurpunt has been working on the expansion and protection of this piece of greenery. The first part is Klein zwitserland Noord. This is still in full cleaning and development.
We reach the Dieseghem farm through the small bicycle tunnel. This farm is the only remnant of the Frankish villa Tissengien, which before the 11th century encompassed today's Mortsel, Hove and Edegem. At the rear of the farm we arrive in Klein Zwitserland Zuid, a beautiful example of a young emerging forest.
After a loop in this area we continue on the former railway verge (or the fort railway) to reach the fort next to the railway line. Fort 4 Mortsel is one of the seven remaining Brialmont forts: fortresses built in 1860-1864 from brick and sandstone. The fort's domain is now a park and the fort itself can be visited with a guide. We walk around as well on the fort, but some parts are closed due to work.