Diliman, located at the center of southern Quezon City, is where many government offices are located, including the City Hall. Diliman is also home to the main campus of the University of the Philippines. Far Eastern University's Institute of Technology (now FEU-FERN College) 15-hectare campus is located at the northern fringe of Diliman. Also in the area are the Philippine Science High School Main Campus, Claret School of Quezon City, School of the Holy Spirit, and Diliman Preparatory School.
At Diliman's center lies the Quezon Memorial Circle the landmark of the city where the late President Manuel L. Quezon is interred. The monument, encased in marble, is the highest structure in that part of the city. Running around the monument is the two-kilometer Quezon Memorial Circle, also known as the Elliptical Road (R-7/C-5). The circle links Commonwealth (R-7/C-5), Visayas, Kalayaan, East, North(C-5), and Quezon Avenues (R-7). The last three avenues provide access to Epifanio de los Santos Avenue (EDSA) (C-4), the main highway in Metro Manila.
The Quezon City Hall, one of the highest city halls in the country is located along the Circle. Surrounding the city hall are spacious parks and open areas. Some of the national government agencies whose head offices are located in Diliman are the:
* Land Transportation Office (LTO)
* Bureau of Internal Revenue (BIR)
* Philippine Nuclear Research Institute (PNRI)
* Social Security System (SSS)
* National Power Corporation (NAPOCOR)
* National Printing Office (NPO)
* Philippine Drug Enforcement Agency (PDEA)
* Dangerous Drugs Board (DDB)
* National Statistics Office (NSO)
* National Housing Authority (NHA)
* Housing and Land Use Regulatory Board (HLURB)
* National Telecommunications Commission (NTC)
* Philippine Institute of Volcanology and Seismology (PHIVOLCS)
* Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA)
* Land Transportation Franchisihng and Regulatory Board (LTFRB)
* Philippine Information Agency (PIA)
* National Computer Center (NCC)
* Occupational Safety and Health Center (OSHC)
* Office of the Ombudsman
* Court of Tax Appeals
* The Departments of Agriculture (DA), Agrarian Reform (DAR), Interior and Local Government (DILG), and the Environment and Natural Resources (DENR).
Surrounding the Circle are many important health centers and institutions. Along East Avenue stands the Philippine Heart Center, the East Avenue Medical Center (EAMC), the National Kidney and Transplant Institute, and the Philippine Mental Health Association. Along North Avenue is the Veterans Memorial Medical Center (VMMC) and the Philippine Health Association. The Philippine Children's Medical Center and Lung Center of the Philippines is located along Quezon Avenue (R-7).
The headquarters of NBN 4, Philippine Broadcasting Service and the ABS-CBN Broadcast Center and GMA Network Center is also located in Diliman.
Most of the rest of the area is residential. Some villages in this portion of Diliman are Teachers Village, U.P. Village, and Sikatuna Village. Those closer to the University of the Philippines campus such as Teachers Village and U.P. Village remain mostly residential although there are two major secondary schools in the area namely Claret School of Quezon City and Holy Family School, and many have converted spare rooms to boarding facilities for out-of-town students attending schools in the area: U.P., Ateneo, and Miriam College. The eastern edge of the Diliman area is roughly bounded by Katipunan Avenue which passes in front of Ateneo and Miriam and runs behind the U.P Diliman campus.