From 2 AD, the expanding Roman Empire established and maintained a series of outposts around and just south of the Danube, the largest of which were known as Carnuntum (whose remains are on the main road halfway between Vienna and Bratislava) and Brigetio (present-day Szőny at the Slovak-Hungarian border). Such Roman border settlements were built on the present area of Rusovce, currently a suburb of Bratislava. The military fort was surrounded by a civilian vicus and several farms of the villa rustica type. The name of this settlement was Gerulata. The military fort had an auxiliary cavalry unit, approximately 300 horses strong, modelled after the Cananefates. The remains of Roman buildings have also survived in Devín Castle (present-day downtown Bratislava), the suburbs of Dúbravka and Stupava, and Bratislava Castle Hill.