You can enter or leave Iran by air, road or sea - but for reasons known only to the relevant authorities, foreigners cannot currently cross the border between Turkey and Iran by train. There's a vast network of flights between Iran and Asia, the Middle East and Europe. Flights between Beirut and Tehran resumed in 1999 after a 20-year absence caused by the Iranian revolution and the Lebanese civil war. Visitors from the USA or Australasia usually have to fly via Asian or other Middle Eastern hubs. Most flights land at Tehran's Mehrabad airport. The situation with the US$30 to US$40 departure tax from Iran is clear as mud - some tickets include it, but many don't.

Currently, it is safe and easy to travel overland into Iran from Turkey (usually at the congested Bazargan/Gürbulak bottleneck) and the more adventurous are successfully crossing into Iran from the former Soviet states of Azerbaijan, Armenia and Turkmenistan. The border with Afghanistan is currently closed and independent travellers are not allowed to cross into Iraq from Iran. Because of the situation in Afghanistan, it is currently not advisable to go overland between Iran and Pakistan. If you're bringing in your own car, be prepared for major delays trying to cross the border - plan ahead and bring loads of patience.

Iran has 2410km (1470mi) of coastal boundaries, but there are only a few ways to enter or leave Iran by sea. In the Persian Gulf, there are ferries from Sharjah and Dubai, United Arab Emirates, and from Bahrain, Kuwait and Qatar. It's also possible to travel across the Caspian Sea on an irregular cargo boat between the Azerbaijan capital of Baku and Bandar-é Anzali.

Although Iran's transport system isn't as developed as those in western countries, it's considerably better than most other countries in the region. All public transport is frequent, reliable, relatively safe and very cheap. But it's worth considering getting airborne for the following reasons: your visa probably won't last long enough for you to use public transport to remote cities; fares are very cheap; the country is vast, and the scenery is often boring; and flights (particularly on Iran Air) are reliable, frequent and cheap.

If you can't get somewhere in Iran by bus (or minibus), chances are that no one wants to go there. There are lots of different bus companies offering competitive and mostly comfortable services. Transport can be a problem for about 10 days before and after No Ruz, the chaotic Iranian New Year which starts on or about 21 March. Road travel can be interrupted by roadblocks at any time of year, most frequently on either side of a main city, but occasionally dotted through remote areas for no particular reason. Foreigners are rarely hassled at roadblocks - the worst that will happen is that you'll have to show your passport and endure a delay.

Trains are fairly efficient, reasonably fast and certainly cheap, but they're often not as convenient as buses, although they are safer and more comfortable (especially for overnight trips). The most exciting trips are between Tehran and Tabriz (for the scenery and excellent service) and between Tehran and Gorgan (for the number of tunnels and the scenery). The great Trans-Iranian Railway, built in the 1930s to connect the Caspian Sea at Bandar-é Torkaman with the Persian Gulf at Bandar-é Emam Khomeini is one of the great engineering achievements of the 20th century.

Driving your own vehicle is a gutsy call. The distances are long, the traffic is appalling and it's hard to find secure parking. To all appearances, there are no road rules. The upside of driving is that the road surfaces are generally excellent and petrol is ridiculously cheap. Shared taxis are a better option between major towns. A seat costs about three times as much as a deluxe bus, but can be worth it if you crave a little extra comfort or want to hurry through a dull stretch of countryside.