The footage in the original trailer for Pokémon Sword & Sheild made it clear that the Galar region was based on the United Kingdom, which was later confirmed by art director James Turner in the run-up to the release of the games. The map of the Galar region is essentially the same as the United Kingdom if it were flipped upside down.
Pokémon Sword & Shield are finally available and fans have had a chance to compare the Galar region to the United Kingdom and it's clear that some of the cities were heavily inspired by real-world locations. Websites like Bulbapedia have put forth their theories about how the Galar region connects to the United Kingdom, and while some areas are composites of different locations, there are definitely some cities that were directly inspired by places in the real world.
Wedgehurst, Slumbering Weald, Wild Area = Cumbria
The starting area of Pokémon Sword & Shield has a lot of visual similarities to Scotland and there are definitely influences there, but areas like Wedgehurst are more closely linked to Cumbria, which is an English county that borders Scotland.
The Wild Area and its numerous lakes are a reference to the Lake District, which is contained within Cumbria. The Lake District is a famous holiday destination in England and is known more for its beautiful landscape than for wandering monsters. The Slumbering Weald is likely based on Grizedale Forest, which can also be found within Cumbria.
Motostoke = Manchester
Motostoke is based on the city of Manchester, which is a city whose history is rooted in its ties to the industrial revolution and the businesses that were created during that era. The close proximity of the coal mines is evidence of this, as this was the natural resource that helped shape Manchester's growth throughout history.
Manchester produced such legendary bands as The Smiths, The Stone Roses, and Oasis, which might be why the Hi-tech Earbuds can be found in Motostoke. The tower in Motostoke is similar in appearance to the clock tower on the Manchester Town Hall in Albert Square.
Hulbury = Liverpool
There are a number of port towns that could act as the inspiration for Hulbury, but its proximity to Motostroke suggests that it's based on Liverpool, which is a city that is close to Manchester in the real-world.
Liverpool was once one of the most important ports in the British Empire and it was a center for international trade, which might be why Hulbury has such a prominent dock and why it's the only place items like incense can be purchased.
Hammerlocke = Birmingham
Hammerlocke is one of the biggest cities in the Galar region, which is why it's likely based on Birmingham, as it's the second biggest city in the United Kingdom in terms of population. The cities of Birmingham and Hammerlocke both have extensive canal networks, to the point where Birmingham has more miles of canal than Venice.
The castle that acts as Raihan's Gym could also be a reference to the fact that Birmingham is close to several different castles, including Tamworth Castle, Kenilworth Castle, and Warwick Castle.
Glimwood Tangle, Ballonlea = Sherwood Forest, Nottingham
Sherwood Forest is the most famous forest in the United Kingdom, due to its association with the myth of Robin Hood. The abundance of fungi in the Glimwood Tangle matches the massive amounts of mushrooms in Sherwood Forest, as it's home to over three-hundred different species of toadstool.
The locations roughly match and it would make sense for one of the only forests in the game to be based on one of the most well-known. The town of Ballonlea is likely inspired by Nottingham for the same reasons.
Circhester = Bath
Circhester is almost certainly based on the city of Bath in Somerset, which gets its name from the famous Roman baths that it was once known for. The Hero's Bath in Circhester and its ancient architecture is a reference to this. The shape of the buildings around Circhester are based on the Circus in Bath, which is a ring-shaped street of houses that are considered a masterpiece of Georgian architecture.
Wyndon = London
The inspiration for Wyndon has been obvious ever since the original map of the Galar region was released during the initial Pokémon Sword & Sheild trailer, as it's meant to be based on London. The large clock tower is obviously based on Big Ben, while the massive Ferris wheel is clearly inspired by the London Eye. Even the names of the two cities are similar. The importance of Wyndon as the location where the Champion battles his challengers is also mirrored in the fact that London is the capital of England.
One of the most disappointing aspects of Pokémon Sword & Shield is that they didn't go further with the United Kingdom parallels. There doesn't appear to be an equivalent to Ireland in the Pokémon world, nor is any mention made of any rivalry between Galar and Kalos, mirroring the real-life animosity between the United Kingdom and France. We can only hope that the Galar region is fleshed out further in a possible upcoming third entry or direct sequels to Pokémon Sword & Shield, possibly in a storyline where the value of the Pokémon Dollar tanks after the Galar region decides to withdraw from the Pokémon League.
Source: Bulbapedia