While the mansion may be the central part of the estate, the grounds also include a boathouse and docks, Japanese gardens, a communications tower, stables and a massive underground complex, which hides from public view the X-Jet runway, hangar bays, the high-speed monorail, which carries personnel to and from the mansion and hangar area, and the special sub-basements of the mansion. An Olympic sized swimming pool is located to the rear of the mansion, along with patios and decking for outdoor entertaining and recreation. The entire mansion and all of the surrounding estate is filled with advanced security systems that detect for intruders.
The Xavier Estate covers a considerable area between Graymalkin Lane and the Breakstone Lake. The first time that there was a body of water mentioned to be on the Estate was in X-Men (1st series) #29, when the X-Men went ice-skating on a frozen “pond.” It is unknown whether this was actually the lake or not, but it was undoubtedly shown during the X-Men’s picnic in X-Men (1st series) #109. Since then, the lake has been an integral part of the Xavier Estate’s portrayal. The residents of Xavier have been shown to spend their spare time at the lake every now and then, and the new mansion seems to be built right next to the edge of the lake. Forge also once used the Lake to stash away the team’s Blackbird jet, when he provided the X-Men with a more capable jet and there wasn’t enough space in the hangar.
There’s a small boathouse by the lake’s shoreline, which was first shown in New Mutants (1st series) #13. While not much used in the early days, eventually the newlyweds Scott Summers and Jean Grey moved into the boathouse to have some privacy. Later, after they had left the team, Gambit temporarily lived in the boathouse because the X-Men had only recently learned of his involvement in the Mutant Massacre and still didn’t trust him.
Right next to the new mansion, there’s now a hedge maze. It sure must be fun for the teenage students to explore it, or to secretly meet there with someone whom they have a crush on. The hedge maze also was the setting for the latest students‘ first Field Day, a specific training where two squads have to compete against each other. [New X-Men: Academy X #3]
Somewhere in the woods, there’s a small shack that Logan built, first seen in Uncanny X-Men #365. It was there that student Angel Salvadore placed her eggs, still confused that her pregnancy cycle was more like that of a fly, rather than a human being. After the babies hatched, she and Beak moved into the shack, where they have been raising the kids together. That is, until the Beak became unhinged from time and was picked up by the reality-hopping Exiles.
Also in the woods, there’s a spot where the walls between dimensions are rather thin. Several times when the N‘Garai demons have tried to invade Earth, one of their cairn materialized there, but each time the creatures were fought back and the cairn was destroyed. [first in X-Men (1st series) #96]
The worst things that ever happen to Xavier are seeing his students dying. On the estate there is a small chapel to mourn the ones that have fallen, along with a graveyard. [first in Uncanny X-Men #304] When the new mansion was built, there was also a memorial garden added, with statues of the deceased serving as a painful reminder to future generations of X-Men that super-heroing is more than plain fun.