Taking place at a construction site for a new business building in New York City in Modern Warfare 3 and in London in Modern Warfare, the map has many choke points and un-finished buildings. The two main spawns are on either side of the map. Hardhat is perfect for close quarters combat, due to its small size, however there are multiple locations where medium range battles take place. There are also one or two long range sight-lines, perfect for snipers. Much of the map is suited to close quarters combat, with sharp corners and short lines of sight. The central building (just south of the actual 'center' of the map) is the main choke point of the map, with four entrances to the area, this building can be hard to defend as enemies can attack from both sides. Teamwork is essential to survive here for long. One of the entrances is a pipe that runs under the map, which often sees intense battles.
The Weapons armory is located outside on the south side of the building near spawn, the Equipment armory is on the southwest side, and the Air Support armory is in the middle of the map, after exiting the tunnel from entering the start side.
Outside of the pipes, there are few spots easy to defend, one such area is the room near the Spetsnaz flag in CTF, which can be used as a position to snipe or provide overwatch for another player, but is vulnerable against air support, flanking and the fuel tank present inside.
There is a dead Spetsnaz soldier hanging from a parachute on the southeast construction building.
There are several opened parachutes laid across the roads outside the map.
There is a burning American flag hanging from one of the cranes.
Rockets can be seen around the map exploding into buildings. There are also fighter jets flying over the map quite regularly.
Church bells can sometimes be heard in the background noise, along with magpies and other birds.
The central building has a sign outside that reads 'Nedzman Place - 100 years in the making' above which is a picture of a glass cube-shaped building, hinting towards it being the final look of the building.
There are several signs around the map reminding construction workers to be wearing a hardhat.
There is a restaurant outside of the playable area that can only be accessed by Spectator Mode, Theater Mode, or with a Recon Drone, called Lenny's. This is an obvious reference to the Denny's line of restaurants.
Among the cityscape, the Trump Building (40 Wall Street) can be seen.
On the map Overwatch, the player can see Hardhat; but on the latter, the player cannot see the former.
A crashed Mi-26 can be seen on a road outside the map past the Delta spawn in spectator mode.