A vertical mall may also be built where the geography prevents building outward or there are other restrictions on construction, such as historical buildings or significant archeology. The Darwin Shopping Centre and associated malls in Shrewsbury, UK, are built on the side of a steep hill, around the former town walls; consequently the shopping center is split over seven floors vertically – two locations horizontally – connected by elevators, escalators and bridge walkways. Some establishments incorporate such designs into their layout, such as Shrewsbury's former McDonald's, split into four stories with multiple mezzanines which featured medieval castle vaults – complete with arrowslits – in the basement dining rooms.