Site3D 2.100 could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this software available. Site3d.exe is the most frequent filename for this program's installer. The software lies within Photo & Graphics Tools, more precisely 3D Design. The actual developer of the software is Microplot Ltd. The most popular version of the tool 2.1. We recommend checking the downloaded files with any free antivirus.
From the developer:
Site3D is a fully featured software product for the engineering design of road systems and housing developments. You can quickly and accurately design whole sites including roads, junctions, roundabouts, footways, surface interfacing, contours, volumes, drainage, housing and more.
You may want to check out more software, such as Smart Map, graphite or Drawing Register Professional, which might be similar to Site3D.