남해오네뜨아파트 is "Namhai honnête apartment" The site is http://www.honnete.co.kr/ 남해 is from a company name "남해종합개발" 오네트 is from a french "honnête" which means honest.

from the pronunciation it seems like namhe onettu apartment.

I think it's correct. I seems that it's name of the apartment.