Prince Charles has started his annual visit to Wales by stopping at the Second Severn Crossing, which has been named after him.
It is now called the Prince of Wales Bridge, despite criticisms following the name change announcement earlier this year.
It is to honour Prince Charles being given the title 60 years ago, and his turning 70 this year.
Monday's change was marked with a ceremony attended by the prince.
The original Severn Bridge will not be renamed.
Tolls on the Severn Crossings are set to be abolished by the end of 2018, the UK Government announced in July last year.
Transport Secretary Chris Grayling said the changes meant that "hard-working families will make savings of over a thousand pounds a year".
Secretary of State for Wales Alun Cairns led Prince Charles and the Duchess of Cornwall of a tour of the Severn Crossing toll office.
"I am delighted that Their Royal Highnesses have been able to join us at this special occasion which marks the start of a new era of cross-border opportunity," he said.
"I hope that the new Prince of Wales bridge and its sister bridge will be seen as positive symbols of the newly invigorated economic, cultural and social opportunities that will present themselves to Wales, helping to make our nation fit for the future."
The Prince and Duchess of Cornwall are spending the week in Wales and will join celebrations to mark the 70th anniversary of the NHS and 150 years of the Heart of Wales rail line.
They form part of 20 engagements lined up for the week.
After the renaming ceremony on Monday the royal couple attended a reception at the Celtic Manor to celebrate business links between Wales and England, along with meeting volunteers of the Gwent Association of Voluntary Organisations in Tintern, Monmouthshire.
Later in the week they will visit Llandaff Cathedral and attend a garden party at Ysbyty Aneurin Bevan in Ebbw Vale, as part of the NHS celebrations.
They will then celebrate Wales' heritage in Builth Wells and visit towns and villages around the country including Crickhowell in Powys and Llandudno, Conwy county.
A music and drama evening is also due to be hosted at their house near Llandovery, Carmarthenshire.