«The UN Buildings complex in Bangkok is the 3rd largest complex owned by the United Nations. The UN Building houses the offices of ESCAP, UNDP, UNEP, UNCDP, UNFPA, UNAIDS, UNIFEM, UNHCR, ILO and UNIS. It also includes the UN Conference Centre, one of the largest convention facilities in Asia.»
-- Source
Outside the building one can find 60 flags of United Nations Members (mainly from Asian and Oceanian countries/regions), and also the UN flag.
As far as I was able to identify them, the list of flags is:
Afghanistan
Palau
Armenia
Papua New Guinea
Australia
Azerbaijan
South Korea
Bangladesh
Russia
Butan
Samoa
Brunei
Singapore
Cambodia
Solomon Islands
China
Sri Lanka
North Korea
Tajikistan
Fiji
Thailand
France
East Timor
Georgia
Tonga
India
Turkey
Indonesia
Turkmenistan
Iran
UN
Japan
Tuvalu
Kazakhstan
United Kingdom
Kiribati
United States of America
Kyrgyzstan
Uzbekistan
Laos
Vanuatu
Malaysia
Vietnam
Maldives
American Samoa
Marshall Islands
Cook Islands
Micronesia
French Polynesia
Mongolia
Guam
Myanmar
Hong Kong
Nauru
Macau
Nepal
France
Netherlands
Niue
New Zealand
Pakistan