I once put a huge number of rabbit holes underground on a single lot. This was because I was trying to play on a tiny island with only about 3 or 4 lots and I wanted a few of the rabbit holes.
About the Witches Village in Dragon Valley I had previously made a fairy village at the unpopulated end of Barnacle Bay too.
https://i.postimg.cc/NMp36RyH/Penelope030.jpg
I used the little brown lines that are all over that world as 'paths' and arranged the extra lots I added in such a way, using fences strategically, so the sims had to travel along the 'paths' to get anywhere.
https://i.postimg.cc/B6mxJny3/Penelope029.jpg
Only problem I found when doing this sort of thing is they get returned to a close by road after alien abductions, and not right back at the house from which they were originally abducted.
Also have to watch not to add too many extra lots. Depends on the computer's processing power and amount of memory available to the game. It can't use more than about 3 GB without risking Error 12 when saving.
https://i.postimg.cc/B6mHCzZC/Penelope022.jpg
https://i.postimg.cc/NMpZKq4W/FelixsHouseWithFaithArrivingForAVisit001.jpg
https://i.postimg.cc/nz04DPZN/TinasPlace002.jpg
https://i.postimg.cc/qR1097XP/FairyVillage003.jpg
All of their living space is in the basements. Above ground you just see small structures that hide the spiral staircase down to their basement homes.