London doesn鈥檛 normally 鈥榙o鈥� entrances, or at least we don鈥檛 anymore. Medieval citizens loved them and throughout the Middle Ages the boundary of the City of London was littered with gated entrance-points.

Neo-classical visionaries revived the idea on a grander scale in the early 19th century with Hyde Park Corner and the now vanished Euston Arch both partially conceived as grand, ceremonial entranceways into the city. But nowadays, the closest we are likely to get to one is a sign on the M1 saying 鈥榃elcome to Barnet鈥�. Hardly inspirational!

Which is what makes the current London Festival of Architecture exhibition in St. Botolph鈥檚 Church in Aldgate so intriguing. Organised by the Architecture Foundation and the Worshipful Company of Chartered Architects, it features competition entries for a temporary new City entrance to be constructed in Aldgate in 2012. It will mark the start of what has been dubbed the 鈥極lympic High Street鈥� which will eventually end at the Olympic Park itself in Stratford. Five entries have been shortlisted and the winner will be revealed on the 22nd July.

As well as providing an innovate means to ensure that the Olympics exerts a urban impact far beyond the Games site, the competition has invited designers to re-interpret historic notions of 鈥榯riumphal鈥� gateways and produce a contemporary landmark that represents London, the Olympics and 鈥� crucially 鈥� Aldgate itself.

With its hostile commercial architecture and tortuous, traffic dominated one-way system, Aldgate has been long derided as a symbol of failed 1960s planning. However, it is currently undergoing a period of significant change, with a partially re-aligned traffic layout and new developments promising a renewed public realm and a more hospitable urban character. All the proposals clearly seek to tap into this new, more aspirational future.

However, they also evidently wish to engage in Aldgate鈥檚 rich and varied past, particularly its historic role as the City鈥檚 oldest mediaeval gateway and the only entrance that admitted all citizens. Etymologists have variously claimed that the origins of the district鈥檚 name derive either from the Old English versions of 鈥�Old-gate鈥� or 鈥�All-gate鈥�. It has also always straddled the point where the wealthy City meets the poorer East End. This wealth of symbolic reference therefore has provided the conceptual impetus for many of the designs.

The fourteen proposals certainly provide a diverse visual and sensual palette with some offerings more surreal than others! Biota鈥檚 鈥楽tate of Aldgate鈥� proposes illuminated vertical columns on a traffic island that forms an interactive 鈥渕ediascape鈥� that pedestrians will be able to temporarily claim as their own sovereign state. The idea is joyfully reminiscent of Ealing Studios鈥� classic comedy, 鈥楶assport to Pimlico鈥�! 鈥楲ondon Gate鈥� by Donis 鈥� shortlisted 鈥� proposes a 100 x 12m 鈥渘aked tower鈥� where a glazed viewing platform will move vertically within a simple steel frame.

鈥楲istening Post鈥檚 by Foster Lomas proposes vertical acoustic posts that will produce an 鈥渋sland of sound鈥�. 鈥楢ldgate to the World鈥� by Juan Alfonso Galan Arquitecto is described as an 鈥渁udio visual icon鈥� that features a tall, solari-type flap destination board that relays various geographic, demographic and physiological information about Aldgate to the outside world. Both schemes are shortlisted.

Casson Castle Architects, Sandy Render Architects and Structure Workshop have proposed a utilitarian archway grandstand that, by allowing people to sit directly on the structure, democratises the traditionally exclusive notion of a 鈥榯riumphal arch鈥�. And 鈥淰ertical Forest鈥� by Sou Fujimoto Architects 鈥� shortlisted 鈥� offers a slender cylindrical tower that is garnished with fulsome greenery and foliage.

All the schemes display a key element that is often lost in architecture 鈥� fun. They provide a means to relate to the history and symbolism of the city and local neighbourhood in a manner that is informative and contemporary yet celebratory also. Modernism, with its uncompromising emphasis on form following function, gave ornamental architecture a tough time. If decoration was out and symbolism could be conveyed in abstract rather than literal terms, what was the point of it? Well the point of it - as this exhibition so imaginatively proves - is to uplift and to inspire. And regardless of which entry wins, for one year at least, a formerly moribund part of London will reap the rewards.

鈥橝 New Landmark for Aldgate鈥� runs from 18th June to 14th of July in St Botolph鈥檚 Church, Aldgate High Street, London, EC3N 1AB. Opens 10.00 - 18.00 Monday to Saturday, 12.00 - 18.00 Sunday.