The Mansion – an opulent, 23-apartment residential property in Marylebone, London is on track to be completed this spring.

Developed by Mayfair-based company Clivedale London, the terracotta-clad building will feature a sunken garden, a 25-metre pool – reportedly the largest in Marylebone – as well as a fitness centre with a sauna, steam room, and private treatment room.

According to DSDHA – the architects who designed the site's master plan – The Mansion was designed to convey a "strong sense of local identity" and prestige.

"The Mansion's complex geometry gently echoes the curve of Marylebone Lane, establishing a presence that is assertive but not overly dominant," DSDHA's director, Dr Deborah Staunt said in a statement.

In order to create an "uplifting" atmosphere, design studio Arney Fender Katsalidis (AFK) outfitted the property's living spaces with burnt oak floors and furnishings comprised of bronze, rose gold, leather, and marble.

The firm also modelled The Mansion's lounge after the leather-panelled gentleman clubs of St James.

Prices for apartments start at £4.95m (US$6.4m, €5.7m).