( dpa )- According to legend, Emperor Frederick Barbarossa met the beautiful Gela 800 years ago on a prominent hill in the town of Gelnhausen in what is now Germany. The story goes that they fell in love and became inseparable from then on. In keeping with that good auspices , it's popular for couples to exchange vows in the town's ancient tower today. They're not the only people looking for unusual venues to celebrate the "most beautiful day of their lives". The austere atmosphere of the registrar's office can be less than romantic and many couples are increasingly looking for alternatives to say the "Yes" word. In Hamburg, for example, hoding a wedding ceremony on the a ship on the River Elbe is gaining in popularity. It costs 275 euros (406 dollars) an hour to rent a ship for a party of 100 guests. Another special wedding location typical for nautical northern Germany is a lighthouse. Captain Wifried Eberhardt organizes lighthouse weddings on the North Sea island of Pellworm , just off Germany's coast. The red and white lighthouse is 40 metres high and Eberhardt promises that its light can safely guide any couple into the port of marriage. A wedding with a champagne reception costs 475 euros. The central German city of Kassel has put an historic tram at the disposal of couples thinking of getting married. The delightful tram is decorated with wooden panelling and costs about 200 euros depending on the time of day and includes a tour of the city. The German capital Berlin has an aquatic theme to offer couples with an elevator that rises and falls through the centre of a 25 metre high aquarium. The city's registrar says the elevator is not meant to symbolise the lows and highs that can come with married life. It costs 55 euros for the registrar to oversee the ceremony. More and more religious marriage ceremonies are not being held in churches. Castles and stately homes can often offer both a chapel and hall to hold a reception. "Getting married in a castle or a mansion has become very popular," says the Bonn-based wedding planner Christine Nett . She advises couples to decide at least 10 months in advance on the date of the big day. "The outlay in comparison to holding a reception at a hotel or restaurant is basically the same," says Nett . She also cautions against inviting too many guests. "It's often difficult to accommodate more than 100 people as historic locations are often small." Monasteries provide another alternative location for conducting a wedding ceremony. Eberbach Abbey in the Rheingau region of western Germany is a former Cistercian monastery with its own branch of the local registry office. "There are priests who can marry couples in a deconsecrated church," says Michael Palmen of the abbey's management. Receptions are held in the abbey's refectory which costs 950 euros to rent. Food and drink have to be arranged separately. Self- organised weddings are often just as expensive as package deals provided by hotels. "If a hotel wedding reception costs about 100 euros per person and a caterer charges 25, it sounds quite cheap at first," says Melanie Schmitz, a wedding planner from Hamburg. But in addition to catering there are also charges for staff, furnishings, decoration, rent for the reception room and a few other costs on top of that. "In the end it often costs just as much," says Schmitz.