City 17
City 17 is a place in 
Half-Life 2.
Introduction
City 17 is the main human population center on Earth under Combine control, and is probably located somewhere in Eastern Europe. The city also houses the Citadel (the as in the only one in City 17; apparently all cities under strict Combine control have one), which serves as an administration center for all Combine operations as well as Dr. Breen's headquarters. A sign in the first map indicates that at least 27 urban establishments with similar names exist.
Architecture
City 17 represents an interesting juxtaposition between the old world and the alien Combine influence. Keep in mind that the very nature of the Combine is to assimilate other species into their power; they adapt rather than destroy and rebuild. Apartment buildings are converted into command centers; sentry towers are attached to tall office buildings; the railway station is being used to transport victims to Nova Prospekt, a human experimentation and augmentation facility. The buildings' original functions should be clear to the player, as well as the Combine's perversion of those functions.
The buzzword for City 17 when Half-Life 2 was in development was "Eastern European architecture". This basically means that buildings should seem old and strong; brick, stone, and to a lesser extent concrete work best. Balconies, pillars, and spires are common. Streets are not built on a grid basis, instead the precise arrangement of roads and buildings has evolved over many hundreds of years. Since it is probable that City 17 was under Communist rule for some decades leading up to the 1990s, it was likely to have been in a dilapidated, outmoded state even prior to the arrival of the Combine.
Certain buildings can appear elaborate if they are for public use - museums, libraries, government buildings, and so on. Refer to the entry on Eastern Europe for more general architectural hints on the region, as well as real-world images.
Environment
City 17 is, obviously, a city, and as such buildings should work as borders for a level. Otherwise, Combine fences or, for smaller gaps, police themselves can be used. Buildings should be large and tall, not only to create better visual blocking but to create a slight claustrophobic feel, which may be desired.
Again, since this is a city, there is considerably less vegetation than other areas. Grassy areas should appear to be gardens or lawns, not open fields. The general sense of disuse and dilapidation means that vegetation is likely to be overgrown and unkempt. Also, since Half-Life 2 appears to be set during the late autumn, trees are almost bare and dead leaves are scattered over nearby pavements.
NPCs
Virtually any NPC will fit in City 17, with perhaps the exception of antlions, as City 17 is probably fortified against wildlife and is located away from the coast. It has been speculated that the machinery at the base of the Citadel works to discourage antlions - Antlions do however appear in City 17 in 
Half-Life 2: Episode One.
Since almost anything can go in the city, wise NPC placement becomes a matter of timing. If making a single-player map, consider when in your storyline this level occurs. If making a multiplayer map that includes NPCs, focus on the player's abilities at the time they would encounter the opponent or ally.
See also
- Eastern Europe - includes real-world examples and reference photography
- Train Station and City 17 soundscapes
- War-torn City 17 soundscapes
- PA announcements for City 17
- Half-Life 2 Sky List - See maps d1_trainstation_01 through d1_trainstation_06 for City 17 before Route Kanal. See maps d3_c17_01 through d3_c17_13 for City 17 after Nova Prospekt.
Reference
Because of the importance of City 17 and the amount of time spent, only major or unique portions of the city will be referenced below.
Train station platform and "reception"
Soundscape: d1_trainstation.Platform
Train station dining hall, news-stand, turnstyles
Soundscape: d1_trainstation.Turnstyle
Train station exterior, Terminal Square
Soundscape: d1_trainstation.TerminalSquare
Backstreets, apartments, playground
Soundscape: d1_trainstation.AppartmentCourtyard
