Possibly, from a police point of view, as long as it does not cause an obstruction or is in breach of other legal requirements e.g. isn't parked dangerously.
When parking your caravan try and park it as considerately as possible for other residents in the street. The caravan/trailer MUST be lit at night if it is parked on a road and comply with the other parking rules - the nearside must face the pavement so the rear lights are at the rear for approaching traffic.
Some local councils also take a strong line on the nuisance value of caravans and do, in some cases, take legal action. It is also worth checking with them before parking on the road - see the website in related information to find your local council.
There may be a restrictive clause in your house deeds, usually inserted by the developers, that prevents you from parking a caravan at you property – we would suggest you check this.
If a trailer is detached from the drawing vehicle and left on a road, at least one of its wheels must be prevented from turning by means of a brake, chain, chock or other efficient device.
If you cannot park your caravan on your property/road, there are sites where you can park caravans off-road.
These rules also apply to any similar trailer parked on a road.