After the destruction, Aspera housed Zane Aren for a while. He used it for his morbid necromantic experiments until he was defeated in the Aren civil war. Few weeks later, Arachnea Aren started rebuilding the Tower in the guise of Leila Aren.
In its current state, the Tower stands higher than ever before. It houses a large training ground prepared specifically for magical training, a library close to equal to the Varrockian, personal rooms for students and teachers, class rooms for theoretical lessons and history lectures, a small battlefield for the Forsworn to train on; Scrying rooms and study rooms, most of which is underground.
The Ground Floor
You head toward the tower, through a field occasionally beset with tents of the Forsworn. There is little forest within a mile of the Tower, but a little desert in places, and something that looks like an impersonation of mountains. This is the "battlefield", the training grounds of the Forsworn. They rarely come all the way to the Tower itself.
Upon entering the Tower from the Grand Arch on its eastern side, you stand on the Ground Floor, more accurately the Lobby. You will be met by a friendly clerk who asks your business, unless you look busy. Looking around, you see a row of lecterns to your right. Each one is engraved with a name, each name that of an Archmage. Some of the lecterns are surrounded bya soft glow, indicating that the Archmage they represent is present at the Tower. Everyone may leave notes to the Archmages on these lecterns. For Notices to all, or a specific teacher, there is the grand pin board behind the lecterns. To your left is the information desk. The "clerks" behind it are tasked with finding any information you might require for you; mainly on the personnel of the Institute. Straight forward you will see two Grand Staircases, one leading up, one leading down and a minor doorway, leading out to the local Harbor. Behind the clerks' desk you can see the Arc leading out to the Mage Training Grounds. This hall is always filled with the buzz of small groups of mages conversing, some coming from the stairs down, some heading from the battlefield to get a decent meal, some heading to the Training Grounds for some serious piratical magic training, and some returning from a mission outside the Tower.
To the south/South-East of the Tower lie the Training Grounds on a medium-sized peninsula. Each of the four elements is found in fitting amounts for training, as well as heaps of bones in a somewhat secluded corner. Aspiring mages with their teachers practice spells of varying difficulty in every direction you look, intense concentration on each face. Farther out, there is a sparring area, where students test their powers against each other, or even their teachers if they feel up to the challenge.
To the east of the Tower is the harbor, with an area to learn swimming, small boats for enjoyable tours in the evening and larger cruisers for the longer journeys students and teachers are sent out to from time to time.
When you ascend the northern staircase to the first floor, you end up in the library. This area is somehow eerily quiet, the only occasional sounds being paper shuffling. The library itself is said to be unending, the walls remaining in view however far you walk into it. It is possible, within the library, to call up a book you require, but this is frowned upon as it is often just as easy to simply walk to the appropriate shelf.
There are sections within the library, each dedicated to a specific type of magic.
Pyromancy: The section obviously houses almost all known knowledge on fire magic. This section is very well lit, and some of the books in it are known to spontaneously combust.
Aquamancy: The section contains all knowledge on water magic that is available. A notable feat of this section is that it always seems to be damp.
Aeromancy: The section addresses air magic. It is by far the hardest section to look for books in, as the books often develop an ability to fly and change their places frequently this way.
Geomancy: The section contains a great number of books and scrolls on earth magic. It is worth remembering that many of these are very heavy, as if the earth called them downwards.
Ice magic: This section addresses all ways of defending against ice magic, as well as some basic ways to utilize it for attacks. The section is well known for its cold atmosphere and books that shatter into pieces if dropped.
Shadow magic: The section contains all knowledge on how to defend against shadow magic. It's a known fact that the section is very dark, and the books are able to shroud themselves in their own shadow, making them almost impossible to find.
Blood magic: This section details Blood magic. Most books here are red, and known to drip a reddish liquid.Smoke Magic: The section addresses Smoke magic, mainly how to defend against it. The air in this section is known to be very thick, to the point of giving people trouble breathing. On occasions, books from this section have been reported to turn into smoke.
The Arcana Macabre: This section is divided in two, the darker one being restricted to all save for the Archmage. It contains all known knowledge on the subject of necromancy, as well as minor tomes detailing basic Galethornian magic. Visitors are advised to bring a good light source and possibly a weapon.
Otherworldly Magic: By far the largest and most inaccessible section of the Library, it houses millions of spells, curses, summoning, rituals and every other imaginable thing not from this world. One should not venture into it alone, and certainly not without a banana; It has been frequently reported that a Orangutan roams the section, attacking anyone who tries to smoke.
Within these sections, some of the books are within special cases. These cases can be opened by teachers of the Institute for use of the students. These tomes are very old, and are not to be brought out of the Institute
The Student Floor
The student floor is the housing of all of Aspera's students. There are dorm rooms and personal rooms for students who need to be alone to concentrate. It is designed to be used mainly for sleeping, but it has some rooms to spend free time in.
The Teacher Floor
The teacher floor is the living space of the teachers who are appointed at the Aren Institute of Magic. It contains a personal room with all facilities for each teacher, as well as three meeting rooms and five Common rooms. The Archmage's rooms are also on this floor, a bit secluded.
The Top Floor
This floor is the place where the Council takes place. It consists mainly of a round table with chairs for the council members. An important note is that magic seems not to work here, or is warped into something completely different than intended. If Aspera were ever attacked again, the magic warping will be removed, and the top floor can be used as the primary defense platform to fire spells from.
In the deepest reaches of the Aspera Underground lies the dungeons. The most fierce of enemies of House Aren are left here to rot until sickness or hunger take them. Not much is known of the prisoners, or the practices that are pushed upon them, however it is safe to assume it is nothing nice.
[Coming soon to Aspera Tower! The below info is merely for reference]
Firstly, the Tower appears to have a portcullis; it doesn't. This is a magical barrier that looks like a portcullis only. One cannot open it, merely pass through, which requires you to possess an Aren Ring. The walls of the tower itself are strengthened by a spell which originates in the catacombs deep below. The dangerous roots surrounding the tower will attack invaders (Just invaders, people approaching with peaceful intentions can pass) on sight, and they are very resilient against anything but magic. To get inside the tower, an invader would have to pass the roots, the defending Arens and undo the protection spell of the tower; which is only possible from the inside.
Planned defense: Major Illusion. The tower looks like a ruin to everyone who is not wearing an Aren Ring.