The town of Lewes is ringed by roughly four housing areas. The Roman/Norman part of the town sits on the strip from the Ouse Valley up to and around the castle site; the housing is arranged loosely around this on the hillsides. If you want flat walking you don't move here as any walk involves a hike up a stiff gradient sooner or later. Why am I telling you this? Well mainly for historical reasons we live at just about the highest point of all this, half way up the Downs, yards from the 1264 battle site.
Now accepted wisdom states that model railways in the garden need to be flat - I don't got flat... I got about a 1 in 15 slope at the bottom which winds up even steeper at the top. So why an I building something outside?
This is true civil engineering: cut-in at the top and raised on a bank at the bottom (the trackbed in the photo is 12" decorative walling blocks). So far I've managed to use bits of walling and tat from around the garden. That's now run out, but track is now down (1" brass screws rather than my usual cut-down Peco pins) and the inaugural light engine ran around the first 10' feet of track with a Mk1 Dr Martin buffer stop in use.
This is all weirdly different from building baseboards.