The first is an international open ideas contest aimed at finding an architectural team, including landscape designers, engineers and planners, to draw up plans for a new market square in Newport, South Wales.
The local city council, the Welsh Development Agency and the Design Commission for Wales are looking for entrants who can create an 'inspirational and contemporary' civic space as well as resolving 'complex transport infrastructure issues'.
A shortlist of up to six schemes will be exhibited anonymously at the Landscape Institute's annual conference in Cardiff on 15 and 16 March and the winning project will receive a £2,500 first prize. There will also be £1,500 and £750 cash prizes for second and third places, respectively.
A RIBA competitions office spokesman said: 'The market square competition represents a fantastic opportunity to design a new northern gateway to Newport city centre and a revitalised connection between its historic core and the River Usk.'
Meanwhile, Corpus Christi College in Oxford is looking for an architect-led design team to overhaul the ancient seat of learning's existing music room.
The college wants to build a 150-seat, multi-purpose auditorium in the place of the smaller music room, built in 1986 into the bastion of the 13th-century city wall.
It is hoped the new £2 million theatre will be able to host a range of functions, including lectures, conferences, performances and exhibitions.
Describing the project, a spokesman said: 'The college's aspirations for the new building are high both in terms of its future contributions to the academic life and commercial opportunities of the institution, as well as the quality of the development, given its historic location within a national monument next to the city cathedral.'
Each of the shortlisted practices will receive an honorarium of £6,000 to develop its designs.
Click herefor more information about both contests.