The Social Development Minister has unveiled the completed public realm works in the centre of Londonderry.
The project includes water fountains and new stone paving, lighting and street furniture in Guildhall Square and Waterloo Place.
Underground utilities including water and gas mains, electricity and telecommunications have also been upgraded and replaced.
Alex Attwood said it was "great news" for the people of Derry.
"This scheme has created an attractive, welcoming city centre space for people and enjoy and has generated tangible economic benefits.
"New businesses have opened and buildings including the Northern Counties, the Custom House, the Northern Bank and the Guildhall either have or are in the process of being refurbished.
"In my view, there is a good argument that pound for pound, government investment in urban regeneration is a key economic strategy out of recession, increasing footfall and creating new shops and new jobs."
The mayor of Derry, Colum Eastwood, said the project was a "major success story for the city".
"The very high quality spaces are a real benefit to the people who live here, who visit the city and are clearly encouraging further investment.
"The scenes we saw during the summer months, when pupils from all our schools interacted freely in the Guildhall Square, demonstrate what a genuine shared space can bring to the city centre.
"I am convinced this scheme will create a platform for future succeses for the city."