( CNN ) -- Seven years after devastating terrorist attacks brought death to New York 's World Trade Centers , the Pentagon and a Pennsylvania field , the first permanent , on-site memorial is being dedicated Thursday at the Pentagon . An artist 's rendering shows the New York 9/11 memorial , with the museum entry pavilion between two pools . Official memorials at the other two sites are still years away . In New York , construction has begun on a complex that will include a memorial with a tree-shaded plaza and reflecting pools , and an underground museum with an entry pavilion . It 's part of a bigger project , including new office towers and a transportation hub , whose target date has been repeatedly delayed . The goal is to open the memorial to the public by the 10th anniversary of the attacks , in 2011 , and the museum by the year after . New York Mayor Michael Bloomberg stressed the importance of those dates and called progress `` frustratingly slow '' in an opinion piece published Wednesday in the Wall Street Journal . `` The memorial must be completed by the 10th anniversary , '' Bloomberg wrote . `` No more excuses , no more delays . '' Watch and listen to Thursday 's memorial services » . However , on CNN 's `` American Morning '' Thursday , Bloomberg said quality is more important than speed of construction . `` We want to make sure what we build is the right thing , that 100 years from now people will look back and say , 'They built it well and built the right thing , ' '' Bloomberg said . `` Nobody 's going to remember if it took five years or 10 years . I 'd like it to go faster . I 've recommended we reduce the level of bureaucracy , but that 's not our number one priority . '' Federal , state and local governments , as well as several agencies and private developers are involved in the planning and construction . `` It 's a complex site , and there was an extensive public process involved in determining the plans for the site , '' Lynn Rasic of the National September 11 Memorial & Museum said Wednesday . `` And I think what 's important now is that we look forward and do everything possible to meet the 10th anniversary date . '' iReport : How are you observing 9/11 ? The Port Authority of New York and New Jersey , which owns the trade center site , says it 's on board as far as the date for opening the memorial . Completion dates for the museum and pavilion are part of a review to be finished by September 30 , Port Authority spokesman Steve Coleman said . `` We do n't want to put any more false hopes , false dates out there in the public domain that ca n't be met . That 's why they want to make sure this thing is a thorough review and we have realistic and achievable dates that we come out with , '' he said . Coleman said the Port Authority has n't felt pressure from families of September 11 victims to speed up the process . `` What we 're hearing from family members is that they want to see it done right , rather than rushed , '' he said . The memorial will feature two huge reflecting pools , with waterfalls flowing down their sides , where the iconic twin towers stood , according to the memorial 's Web site . Engraved around the pools will be the names of those who died in the September 11 attacks as well as the victims of a 1993 terrorist attack on the World Trade Center . Watch and listen to sights and sounds from 9/11 » . The steel and glass entry pavilion will include two large steel columns salvaged from the twin towers . As visitors descend underground into the museum , they 'll see the slurry wall , the bedrock that held back the Hudson River when the towers collapsed . The Pennsylvania memorial is also scheduled to be completed by the 10th anniversary of the attacks . It will center on the site where United Flight 93 crashed after passengers apparently wrested control of the plane from the hijackers . A plaza will surround the crash site , known as Sacred Ground . Plans call for a Tower of Voices , with 40 windchimes representing the 40 passengers and crew members who died . The Pentagon memorial , opening Thursday , includes a bench , a tree and a pool for each of the 184 people killed there when another hijacked airliner crashed into the building . Watch a victim 's family tour Pentagon memorial » . The areas are arranged in order of the victims ' ages , ranging from the youngest , 3-year-old Dana Falkenberg , to the oldest , John D. Yamnicky , 71 , according to a Defense Department Web site . `` When we learned that there were five children who lost their lives that day , that 's really what sparked the idea , '' designer Keith Kaseman said . To read the name of a person killed in the Pentagon , a visitor must look toward the building ; if the victim was on board the airplane , the name can be seen by looking up . After dedication ceremonies , the memorial opens to the public at 7 p.m . ET . `` This place is really all about the visitor 's thoughts , your interpretation , '' Kaseman said .
World Trade Center memorial plaza scheduled to open in 2011 , museum in 2012 . Memorial at Pennsylvania plane crash site also due to open in 2011 . Comment: Watch 9/11 memorials in New York and Washington on CNN.com Live .