I've posted a few images of my observatory when I finished it back in 2017. Since then, I have moved from the 24" Starmaster, which was the reason for building observatory #2, back to German EQ mounts.
Since the observatory is 16'x16', I have enough room to comfortably house two nice scopes.
There are two piers with early Astro-Physics 1200 mounts on them. Both piers are 8" square by 1/4" thick walls.
The pier packing the newtonian extends through the floor, into the ground about 36", and is in about 2000# of concrete.
The refractor pier is anchored to the original concrete floor of observatory #1 via a 24" X 24" x 1/2" steel plate and stainless steel anchors. I filled this pier with very coarse sand to help dampen vibrations.
As seen in the images, the piers are isolated from the floor.
What I really like is the fact that there are no ladders for the newtonian. And after standing on concrete all day, I can come home, hit the button for the motor to roll the roof off, and I can sit in my comfy chair to observe through the refractor.
Just to give those who are contemplating building a roll off something to consider, when I built #2, I built a kick out so the desk is out of the observing area. Also, it helps keep dew off of the charts and such.
If you are wondering as to what the scopes are; the newtonian started out as a 12.5" f/6 Meade Research Grade OTA. I cut the tube down and installed a Pegasus Optics 12.5" f/4.9 with a Strehl ratio of 0.995 and a Antares 3.1" 1/30 wave diagonal for imaging. It has a Starlight Feathertouch and a Takahashi 11x70 finder as well. The scope is a joy to use and produces wonderful images.
The refractor is a late 1990's Meade ED/APO with a 2.5" Moonlite focuser. It has the later lens cell design, along with a really nice lens.
The mount under the newtonian is a 1200 DA. Under the refractor is a 1200 QMD. Both have digital setting circles.
With the upgrades I completed over the summer, into early fall, I really enjoy going down and using it more often.