Horse and Carriage
Perhaps an old fashioned method of travel will suit your wedding theme.
If you would like to use a horse and carriage, it is essential to use a local company, and ensure that the distance you need to travel is only short.
Always inspect the carriage and make sure the horse is well cared for. Make sure you check what the driver will be wearing.
There is no way to predict the weather, so check that there is an adequate canopy - you don't want to have your dress ruined en route if the heavens open.
Even the most sensible horses can get jittery in very heavy traffic. You may need to choose your route carefully and allow extra time for this.
Don't be pressured by convention. If you want to arrive in such a way to make your guests gasp or leave in a boat (location permitting!), hot air balloon, on horseback or any other way you fancy, then do it!
Be sure to plan any unconventional means of transport well in advance so that you have a chance to find suppliers, check the feasibility of your dream transport and make alternative plans if there are any problems. Whilst you may be delighted to travel in something a little strange, don't forget to make sure the best man makes appropriate arrangements for the bridal party, and any guests that may need help with transport.