OK, this is my first submission, I'm not an artist in any way! This is a development of a hand-drawn covenant (home base / castle) for a group of mages in a role-playing game I used to play.
The original version was a circular tower drawn on 1/5/10mm cyan on white linear graph paper. This version was produced in Microsoft Visio Professional 2003. Each level (of which there are about 20 including the caves) was designed from the previous using copy / paste / edit to ensure accurate duplication of features on more than one level (stairs, etc.) and alignment of windows, etc.
The covenant is a self-contained medieval society designed to support its mages, with most of the tradesmen available in a large village and other more esoteric arts such as book-binding and glass-blowing. Mages have a lab and sleep area and there are several communal areas for their support crew.
The advantage of Visio is its ability to handle vector-based images, its biggest flaw is the lack of decent texture or gradient fills for objects, leading to a rather flat appearance in line with modern site and house plans. It has a variety of building elements such as windows, doors, etc, which can be resized, coloured and opened and closed. It's greatest problem is the 'snap-to-object' feature. While this allows the program to merge walls to each other and eliminate the joins between them, it can also put things where you don't want them or jump them from one wall to another.
This plan had various iterations, each representing a stage in the growth of the covenant to its present size, from single tower, through triple tower in 'Mickey Mouse' layout, with others being added over time, including one which climbs the side of the cliff, 'conveniently' the right distance away from the original tower to permit this expansion. It forms the link between the older, lower and upper, newer covenant.
I added caves using the freeform curve tool. It's not great, producing smooth curves representative of overall shapes rather than the roughness of natural caves, but hand-drawn shapes are hard to manage in Visio.