Like every other ancient city in Europe, Utrecht once had impressive city walls, but in the 19th century they lost their purpose so the city council tore them down and created public parks in their place. The result is a 5km-long strip of green space known as Zocherpark / Singelarea that is especially pretty at the southwestern and eastern ends of the historic city centre. The long, narrow strip is not only a National Heritage site, but also provides the city's residents with a place to escape the hectic heart of the centre. The Zocherpark is one of the oldest public parks in the Netherlands and includes more than 400 trees dating back to the mid-1800s.