The Thames basin, traditionally known as low lying land and with problems of flooding and drainage has been somewhat tamed by the Thames Barrier, that protects London against the spring time surges from the North Sea.

The North bank of the Thames, elevated and well drained comprising of terrace and capped by brick earth, was also fairly level. This combination of high, flat and safe ground (the Thames had a habit of breaching its banks and carrying invaders such as the Vikings) and fertile land proved a popular area to build upon even back in the days of the hunter-gatherers. The south bank was not as heavily populated, with exceptions of the higher ground in Southwark providing isolated homesteads.

However, the past history of flooding, marshlands and estuary deposits have left a geotechnical minefield for the high rise developments of the present time.

Fortunately, foundation technology is well founded on the stiff London clays, and plateau gravels which, with the wealth of test results, give reliable predictions, but as the land rises to Hampstead Heath in the North and Crystal Palace in the South, this reliability gives way to the fissured soft brown clays that are prone to the moisture requirements of local vegetation and the resulting ground movements.