This peaceful memorial park is dedicated to Thich Quang Duc, the Buddhist monk who self-immolated in protest at this intersection not far from the Presidential Palace (today's Reunification Palace) in 1963. The memorial was inaugurated in 2010, displaying Thich Quang Duc wreathed in flames before a bas-relief.
Note that Thich Quang Duc has been elevated to the status of a Bo Tat on the memorial, which means a Boddhisattva (an enlightened person who forgoes Nirvana in order to save others).