Bute Park is the "Green Heart" of Cardiff, Wales. It is the largest urban park in Wales and easily accessible from the city center. The park along with Cardiff Castle is listed as a Grade 1 Historic Designed Landscape. Cardiff Castle, the Animal Wall, the Gorsedd Stones and the Blackfriars site are just a sample of the park’s rich history. The Blackfriars site dates from the 12th century and is deemed to be the second most important friary site in Wales. The Arboretum contains a mix of interesting trees many of which are champion trees, the largest in the UK. The park highlight is the Royal Horticultural Society Show held annually in April.