Where do most foreigners live in Korea?

Excuse me, I'm quite fascinated by Korean culture and I'm planning to visit Korea in the near future. I'm curious about the demographics of the country, particularly the distribution of foreigners. Could you tell me where most foreigners tend to reside in Korea? Are there any specific areas or cities that are popular with foreign residents, perhaps due to their proximity to international schools, businesses, or cultural hubs? I'd appreciate any insights you could provide.