Not a subject for every dinner table, but worth knowing in case you should be unlucky enough to get a blocked drain or a flood. At least the London Assembly knows which way the drains flow... The London assembly have released a draft document for sustainable urban drainage (SUDS) which contains this image of the main sewer network of London:

This plan shows a small fraction of London's invisible underground architecture, the scale it is plotted at reveals the geomorphology underlying this most urban of infrastructural developments.

It won't help the average householder very much, but

The Royal Horticultural Society (RHS) is unveiling plans to create a stunning new 156 acre RHS Garden in the heart of the North West by bringing back to life the lost historic grounds at Worsley New Hall in Salford. The site forms part of the 3rd Duke of Bridgewater’s estate and adjoins the Bridgewater Canal in Worsley, Salford. RHS Garden Bridgewater is planned to open in 2019 as part of the RHS’ wider ten year £100+ million investment programme to achieve its Vision to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.RHS gets a new gardenRHS unveils new 156 acre garden in Salford.

Details are here