Wales is a generally mountainous country on the western side of central southern Great Britain. It is about 274 km (170 mi) north-south and 97 km (60 mi) east-west.
The oft-quoted 'size of Wales' is about 20,779 km² (8,023 sq mi). Wales is bordered by England to the east and by sea in all other directions: the Irish Sea to the north and west, St George's Channel and the Celtic Sea to the southwest and the Bristol Channel to the south. Altogether, Wales has over 1,180 km (730 mi) of coastline. Over 50 islands lie off the Welsh mainland; the largest being Anglesey, in the northwest.
Much of Wales' diverse landscape is mountainous, particularly in the north and central regions. The mountains were shaped during the last ice age, the Devensian glaciation. The highest mountains in Wales are in Snowdonia (Eryri), of which five are over 1,000 m (3,300 ft). The highest of these is Snowdon (Yr Wyddfa), at 1,085 m (3,560 ft). The 14 Welsh mountains, or 15 if including Garnedd Uchaf - often discounted because of its low topographic prominence - over 3,000 feet (910 metres) high are known collectively as the Welsh 3000s and are located in a small area in the north-west.
The highest outside the 3000s is Aran Fawddwy, at 905 metres (2,969 feet), in the south of Snowdonia. The Brecon Beacons (Bannau Brycheiniog) are in the south (highest point Pen-y-Fan, at 886 metres (2,907 feet)), and are joined by the Cambrian Mountains in Mid Wales. The highest point being Pumlumon at 752 metres (2,467 feet).
Wales has three national parks: Snowdonia, Brecon Beacons and Pembrokeshire Coast. It has five Areas of Outstanding Natural Beauty. These areas include Anglesey, the Clwydian Range, the Gower Peninsula and the Wye Valley. The Gower Peninsula was the first area in the United Kingdom to be designated as an Area of Outstanding Natural Beauty, in 1956.
Forty two percent of the coastline of South and West Wales is designated as Heritage Coast, with 13 specific designated strips of coastline maintained by the Countryside Council of Wales. As from 2012 the coastline of Wales has 43 Blue Flag beaches and five Blue Flag marinas. Despite its Heritage and award winning beaches; the south and west coasts of Wales, along with the Irish and Cornish coasts, are frequently blasted by Atlantic westerlies/south westerlies that, over the years, have sunk and wrecked many vessels. On the night of 25 October 1859, over 110 ships were destroyed off the coast of Wales when a hurricane blew in from the Atlantic. More than 800 lives were lost across Britain because of the storm, but the greatest tragedy was the sinking of the Royal Charter off the coast of Anglesey in which 459 people died. The number of shipwrecks around the coast of Wales reached a peak in the 19th century with over 100 craft losses and an average loss of life of about 78 sailors per year. Wartime action caused losses near Holyhead, Milford Haven and Swansea. Because of offshore rocks and unlit islands, Anglesey and Pembrokeshire are still notorious for shipwrecks, most notably the Sea Empress Disaster in 1996.
The first border between Wales and England was zonal, apart from around the River Wye, which was the first accepted boundary. Offa's Dyke was supposed to form an early distinct line but this was thwarted by Gruffudd ap Llewellyn, who reclaimed swathes of land beyond the dyke. The Act of Union of 1536 formed a linear border stretching from the mouth of the Dee to the mouth of the Wye. Even after the Act of Union, many of the borders remained vague and moveable until the Welsh Sunday Closing act of 1881, which forced local businesses to decide which country they fell within to accept either the Welsh or English law.
The Seven Wonders of Wales is a list in doggerel verse of seven geographic and cultural landmarks in Wales probably composed in the late 18th century under the influence of tourism from England. All the "wonders" are in north Wales: Snowdon (the highest mountain), the Gresford bells (the peal of bells in the medieval church of All Saints at Gresford), the Llangollen bridge (built in 1347 over the River Dee), St Winefride's Well (a pilgrimage site at Holywell) in Flintshire, the Wrexham (Wrecsam) steeple (16th-century tower of St Giles' Church, Wrexham), the Overton Yew trees (ancient yew trees in the churchyard of St. Mary's at Overton-on-Dee) and Pistyll Rhaeadr - a tall waterfall, at 240 ft (73 m). The wonders are part of the rhyme:
The English words "Wales" and "Welsh" derive from the same Germanic root (singular Walh, plural Walha), which was itself derived from the name of the Celtic tribe known to the Romans as Volcae and which came to refer indiscriminately to all Celts and, later, to all inhabitants of the Roman empire. The Old English-speaking Anglo-Saxons came to use the term Waelisc when referring to the Celtic Britons in particular and Wealas when referring to their lands. The modern names for some Continental European lands (e.g., Wallonia and Wallachia) and peoples (e.g., the Vlachs via a borrowing into Old Church Slavonic) have a similar etymology.
Historically in Britain, the words were not restricted to modern Wales or to the Welsh but were used to refer to anything that the Anglo-Saxons associated with the Britons, including other non-Germanic territories in Britain (e.g., Cornwall) and Germanic territories particularly associated with Celtic Britons (e.g., Walworth in County Durham and Walton in West Yorkshire), as well as items associated with non-Germanic Europeans (e.g., the walnut).