Matilo (or Matilone) was the name given to a Roman fort in the Netherlands, in what is today the city of Leiden. It was part of the Roman border defences along the River Oude Rijn (literally, “Old Rhine”), located in the province of Germania Inferior. Two other forts nearby were located at modern Alphen aan de Rijn and Valkenburg; all three are located in the modern province of Zuid-Holland.
The castellum at Matilo was constructed shortly after the Batavian Revolt of AD 69/70. The originally wooden constructions were replaced over time by more sturdy structures, such as outer walls made of tufa and a stone headquarters. The fort remained in use for about a century and a half, and was abandoned between AD 240 and 260. The stone from the fort was eventually removed and re-used elsewhere: the remains of the keep (“Burcht”), located on top of a motte in the centre of Leiden and dated to the eleventh century AD, contain pieces of stone that must have originally come from the castellum.
To mark the site, it was turned into an archaeological park, located between the modern neighborhoods Roomburg and Meerburg. It features a partial reconstruction of the fort’s superstructure. If you visit it today, you can see reconstructions of the earthen sections of the walls and a modern interpretation of the watch towers at each of the main gates. Originally, the walls would have been topped with wooden palisades.
The fort was already made into a national monument in 1976. Archaeological investigation of the fort itself has been limited so far in the belief that future techniques would do a better job at unearthing the secrets buried here. Nevertheless, due to construction work in the surrounding area, soem fascinating ancient objects have come to light. From the Fossa Corbulonis (a canal dug on the orders of the general Corbulo in ca. AD 50), near Matilo, archaeologists recovered an impressive cavalry mask in 1996. The mask dates from the end of the first century AD. It is now part of the Roman collection of the National Museum of Antiquities in Leiden (source):
Park Matilo is open to the public and can be entered at virtually any time of day at no cost. There are various signs scattered in and around the park with information about the Roman fort, as well as evidence from later times. It is located outside of the centre of town. You can get there from Central Station or the train station at Lammenschans by bus. You can also walk to the site, but it will take you about 30 minutes from Lammenschans (and longer from Central Station).
The park has a website, but it’s only available in Dutch.