In Victorian times, mass-produced flatirons were used in pairs: while one was in use, the other was warmed by an open fire. Their shape is similar to an isosceles triangle: a triangle that has two sides of equal length. The difference is that the equal sides curve outwards before coming to a sharp point. In addition, the third side is less than half the length of the two curved sides.
Across the UK, there are many pubs which have a shape similar to the flatiron. They are usually built on an acutely angled corner site and often have a wedge-shaped corner, not the classic sharp point.
One local example is the Three Tuns on Silver Street Head in the centre of Sheffield. Built in 1840, this Grade II listed building was originally multi-roomed, taking on its current internal layout in 1976. It is an exception to most pubs of this shape in that the wedge side is not used as an external door. Instead, as illustrated by both the map and the photo, it is like sitting in the bow of a ship.
Other examples include the ornate Grade II* listed, Barton Arms in Birmingham. Dating from 1900-01, this is much larger than the Three Tuns and has a very large wedge for the corner. Closing in 2000, it was reopened by Oakham Ales in 2003.
Located within a converted RBS bank and opened in late 2017, RedWillow Buxton also exhibits the classic shape. Passing through the double wooden entrance doors, the large original entrance area leads, via a wood-panelled porch, to a further set of double doors and into the bar area. Original ornate carved wood is above your head as you enter. In addition, an original mahogany and glass office space to the right of the bar, holds tables and large leather chairs. Two original brass hooks (for hanging jackets/coats) remain from the days of bank-use. Above the entrance to this space is original carved woodwork.
Many more exist: between us, can we name them all?