The Wye valley walk and Offa's Dyke are both nearby - see the TI link
Local Towns
The nearest town to Glasbury is Hay-on-Wye, about 3 miles away. Hay is famous for being the 'Town of Books' (37 second hand bookshops at the last count, including the world's largest), and for its annual star-studded Literary Festival each May half term. Brecon is a 10 minute drive, and has a leisure centre and a theatre Theatr Brycheiniog. Hereford is a 30 minute drive and is worth a visit to see the Cathedral with its Chained Library and Mappa Mundi Exhibition. You can also visit the Bulmers Cider Museum, and do a tour of the Bulmers factory.