Some thoughts about the site location which need to be jotted down.
The final tourist attraction is likely to be at least partially undercover to attract the wet weather tourists. I have had some thoughts about a big aircraft hanger but I am not sure you will find just one on their own and it would be a bit of an ugly building. Although it would be worth bearing in mind as an old aircraft hanger would be an excellent empty shell for an indoor maze, perhaps with a mezzanine deck to look down into the maze.
Old Victorian mill / warehouse
Again probably in short supply but if there did happen to be an old mill / warehouse it would be the perfect empty shell. This time unlike the aircraft hangar it would be a picture perfect location especially if it had a running stream by the side.
Garden / outdoor space
There is going to be a need for adequate parking, should also think about nearby public transport links. There will also be enough land for gardens and outdoor mazes. By in large the site should be flat or gently undulating. Hillside at one end of the site could be interesting as there is an idea for a snakes and ladders maze.
Think about prevailing wind and site shelter from south west storms. Definitely consider counting the number of mature trees or start planting new trees early in site development.
Access to the national road network should be considered, nearest motorway junctions, nearest A roads, how many routes to the site etc.
Check public access routes, make sure there are no footpaths or bridal ways which would allow free access to the site circumventing paid for access.