Bratislava has a very pleasant medieval inner city with narrow, winding streets, a hill-top castle next to the river Danube, and many historic churches and buildings to visit. The old town is centered on two squares, Hlavne namestie (main square) and Hviezdoslavovo namestie (Hviezdoslav square, named after a famous Slovak poet). Of a rather different architectural character are some of the communist-era buildings found in the modern parts of the city; a prime example is Petrzalka housing estate, the biggest Communist-era concrete block housing complex in Central Europe, which stretches on endlessly just across the river. Move further east and there are plenty of rural places to explore. Farms, vineyards, agricultural land, and tiny villages are situated less than 50 kilometres to the north and east of Bratislava.