The city is found in a shallow valley and divided by its river. Alicante rises up the side of a steep hill on one side, and its houses pile atop one another. The construction is mostly in gold- and honey-colored stone, with red tile roofs. From the river, canals have been dug, of which the largest is Princewater Canal. Apart from its unusual demon towers, Alicante is a city of canals, since wells must be kept shallow to avoid piercing the adamas veins below the city.
The only Portal that opens directly into and from Alicante is the permanent one in the Gard. There are wards (specifically the towers) and laws preventing entering directly into the city magically without explicit permission and the opening of the Portal, with people waiting, on their side; attempting to do so would only open a Portal as close to the city outskirts as possible, such as above Lake Lyn. Past the lake, Alicante can be reached by traveling past Brocelind Plain and Brocelind Forest.
By tradition, Downworlders are permitted to enter the city only through its north gate.
Alicante began as a small settlement in the center of a ring of demon towers to a large, bustling city, eventually needing to clear the Brocelind Forest to accommodate the growth of the city.
- Main article: Demon towers
The demon towers that surround Alicante control and support the wards, helping protect the city from demons. They were set up in such a way that they can only be deactivated with demon blood from within the city; since demons cannot enter Alicante, it was the perfect paradox. Fortified for years, the city was caught by surprise when Valentine's demon army was able to enter Alicante, after Sebastian Morgenstern used his demon blood to deactivate the demon towers in September 2007.
The towers can also light up to alert its citizens of certain situations; an example is their red and gold battle lights that signal the people of Alicante to get to the Gard.
Because of the wards that surround Idris, Alicante is powered primarily by witchlight, and communications are made primarily through letters and fire-messages, as no electricity or modern machinery is known to work reliably within the borders.
It is for the towers' glass-like appearance that Alicante was dubbed a "city of glass".
- Main article: The Gard
The only Portal open in Alicante, for the use of the Clave in times of emergency, is in the Gard. Because of the demonic Marks on every Portal's frame, the Portal and the whole room containing the Portal is "reverse-warded", where it is blocked off as a place outside the protection of the wards, much like an Institute's Sanctuary. Because of the risk, the exact location of the Portal is a closely guarded secret.
Angel Square is the plaza located at the city's center, considered one of Alicante's most picturesque and historically relevant spots. Fitting of its name, a bronze statue of the Angel Raziel—the largest in the world—stands in the middle of the plaza. At the northern end of the square is the Accords Hall.
- Main article: Accords Hall
The Great Hall of the Angel is the general meeting hall for all Shadowhunters. It became known as the Accords Hall after being used as the location for the historic signing of the First Accords in 1872.
In other times, the Hall is the site of celebrations, ceremonies, weddings, and festivals.
The Armory is an imposing stone stronghold on the eastern side of Alicante, part storehouse, part museum, part research center. The Armory serves the same function for Alicante as the weapons room does for an Institute. Weaponry is taken from here for Shadowhunters in case of conflict within Idris. Non-members of the Clave are restricted to the south wing, which serves as a museum that showcases a collection of antiquated and famous, legendary weapons.
The Armory is the only place within Idris proper that the Iron Sisters are known to be seen, although they mostly stay below ground level in its extensive and labyrinthine basement levels, working on new weapon designs and performing repairs, among others. A passage somewhere in those basement levels is said to lead directly to the Adamant Citadel.
- Because there is a city called Alicante in Spain, the fictional city is spelled "Alacante" in Spanish editions.