Llanidloes (ɬanˈɪdlɔɨs) is a town and community on the A470 and B4518 roads in Powys, within the historic county boundaries of Montgomeryshire (Sir Drefaldwyn), Wales. The population in 2011 was 2,929, of whom 15% could speak Welsh. It is the third largest settlement in Montgomeryshire, after Newtown and Welshpool. It is the first town on the River Severn (Afon Hafren), counting from the source. The town's Member of Parliament is the Conservative Craig Williams (MP since 2019) and its Member of the Senedd is Conservative Russell George (MS since 2011). The town is close to the large dam and reservoir Llyn Clywedog. There is a scenic mountain road connecting Machynlleth and Llanidloes. Llanidloes is popular with hikers who walk on the scenic footpaths surrounding the town, including Glyndŵr's Way, which in conjunction with the Offa's Dyke path forms a 160-mile circuit around Mid Wales and local passage over the spine of the Cambrian Mountains. The Sarn Sabrina Walk – a 25-mile circular walk from Llanidloes to the source of the Severn and back – has been held yearly on the Saturday preceding the Late Spring Bank Holiday since 2006. In 2007 the Semi Sabrina, a 12-mile circular walk, was added. The Hafren Forest is also used for car rallies such as Rally GB and motorcycle Enduro events throughout the year. Llanidloes takes its name from the early 7th century Celtic Saint Idloes (Llan-Idloes = the Parish of St Idloes), after whom its parish church is named. The village hall is the centre of Wales. It was then part of the cantref of Arwystli. In 1280 Llanidloes received a market charter from the King (granted to Owen de la Pole) and the benefit of Edwardian town planning and earthwork defences. The present-day street plan follows the 13th century grid layout. O'Neill traced earth bank defences from the confluence of the Severn with the Clywedog and along Brook Street on the north, beyond High Street on the east, and along Mount Street on the south; with the Severn forming the western boundary.