The National Trust was founded in 1895 by three Victorian philanthropists - Miss Octavia Hill, Sir Robert Hunter and Canon Hardwicke Rawnsley. Concerned about the impact of uncontrolled development and industrialisation, they set up the National Trust to act as a guardian for the nation in the acquisition and protection of threatened coastline, countryside and buildings.

Now in its 117th year, the Trust today cares for over 248,000 hectares of beautiful countryside, more than 700 miles of coastline and more than 200 buildings and gardens of outstanding interest and importance in England, Wales and Northern Ireland. Most of these properties are held in perpetuity and so their future protection is secure. Thousands of archaeological sites, historic buildings and cultural landscapes can be found right across our properties, all of which are cared for and managed by the Trust's specialist conservation team, which includes professional archaeologists.

Much of the archaeologists' work within the Trust is involved with the conservation and interpretation of archaeological monuments, industrial sites, historic parks and gardens, vernacular buildings, historic houses, historic landscapes, artefacts and archives - in other words, the entire historic environment. It is this focus on conservation that has meant the Trust's archaeologists are less often involved in the process of archaeological excavation, so when Time Team suggested the work at Gateholm and Watery Bay Rath, two of the more enigmatic prehistoric monuments on our property in Pembrokeshire, we were naturally cautious.

The National Trust is a registered charity and is completely independent of Government, and relies almost entirely for our funding on the generosity of our subscribing members (now numbering more than four million) and other supporters. It is important that we live up to our members' expectations in our actions as a conservation body and consider any proposal for archaeological excavation carefully, as excavation is in itself a destructive process. Before any digging can be contemplated, it is vital to weigh up any possible benefits compared with the risk of irreversible damage to a site which has stood undisturbed for thousands of years.

From the outset it was critical that, if we were to go ahead with Time Team's proposed work, a clear set of research objectives needed to be identified which related to the current research framework for archaeology in Wales. These objectives would have to produce information that could help us not only in our understanding of these mysterious sites but also, and perhaps more importantly, in our long term management and conservation work. An additional factor in considering this project was the Scheduled Ancient Monument status awarded to the two sites by Cadw (the Welsh Government's historic environment service), therefore any decision to be made would need to be collaborative.

It was also essential that the Trust worked together with the Pembrokeshire Coast National Park Authority (PCNP), as well as with Dyfed Archaeological Trust (DAT).

Despite our reservations, there were some obvious benefits in deciding to go ahead with the work, not least the opportunity it would afford the Trust in our aim to bring our places to life and enrich our understanding of our archaeological resource. Finally, after a lot of hard work from everyone involved we agreed that the project could go ahead, and before we knew it the day had arrived. Time Team appeared and the work began in earnest on Gateholm and Watery Bay Rath.

The three days with the Time Team passed quickly and the weather was kind, well some of the time, enabling a great deal to be achieved in a relatively short time.

The sensitive nature of the scheduled ancient monument meant that all excavation had to be undertaken by hand without the help of machinery making the excavator's task all the more challenging not to mention the difficulty of getting people and equipment across to Gateholm which had to be accessed via a zip wire!

The work itself revealed some exciting archaeology and some interesting finds including an amber bead from Gateholm and some unexpected flint tools found in the field behind the Rath.

The work also demonstrated the high level of preservation of archaeology within the Rath and conversely the fragile nature of the archaeology on Gateholm.

The whole project was a great success and the work done has added significantly to our understanding of the sites and has helped us to formulate our plans for future management. We appreciated the enthusiasm and professionalism of the members of the Time Team crew and would like to thank them for their sensitive approach to these very special archaeological sites.

More work is scheduled for Gateholm and Watery Bay Rath at Easter 2012, which will be carried out by the National Trust in conjunction with PCNP.

We will be field walking and looking for flints in the fields behind the Rath. We're looking for volunteers join us in this exciting opportunity to continue to investigate the archaeology here.

If you would like to find out more about the archaeology of South Wales, where Gateholm and Watery Bay Rath are situated, or for more information on archaeological sites throughout Wales, I recommend you to visit www.archwilio.org.uk