Back in 2015, while learning level design, I tried CS Map making. Starting off creating maps/levels for counter-Strike 1.6 using Valve Hammer Editor (Ver 3.1) provided in the Source SDK. Valve Hammer Editor is a tool primarily used for developing the architectural background of the level, object placement, texture-mapping, lighting, and the object interaction with the player entity.

I’ve created two versions of the same map.
de_deathmatch - This version has the classic deathmatch scenario between counter-terrorists and terrorists. Terrorists have to find the bomb site inside the building and plant the bomb. Counter-terrorists have to kill all the terrorists and/or defuse the bomb before it goes off.
cs_dept_hostage - Hostage rescue. Inside the building, there are 8 hostages that need to be rescued by the counter-terrorists.
This map can be played in both Counter-Strike 1.6 as well as in Counter-Strike:CZ. I tried to run it in CS:Source, but it needs to be converted completely. The textures have to be changed, the entities and models are different. And so, I scrapped it. This map is tested on both 1.6 and CZ, and it runs fine. Lowest fps recorded is 26 fps which should be fine with all latest PCs.