Aachen is a city in North Rhine-Westphalia, Germany, at the point where Germany borders on Belgium and the Netherlands. Historically this spa-town was a prominent city, the place where the German Kings were crowned, and a famously favoured residence of Charlemagne who still lies buried in the impressive cathedral he himself had built. The city is packed with historic sights that remind of those days, including medieval buildings, city gates and beautiful fountains.
Today, Aachen has become a pleasant mix of historic (often Baroque) grandeur and modern innovation. It has a population of 246,000 and is home to a large and highly regarded university. All in all, a place well worth visiting.
In French (including crossborder train services from Brussels and Paris), the city is known as Aix-la-Chapelle, the city is called Aquisgrán in Spanish, whereas its Dutch name is Aken.
Trains from Cologne (to Cologne €16-19 per person) and Düsseldorf run every half hour; express trains (Regional Express) take about an hour and local trains (Regional Bahn) take 90 minutes. Four times per day, high speed train (Inter City Express) goes from Frankfurt through Cologne and Aachen to Brussels. German railway company Deutsche Bahn 
Aachen shares its own airport with Maastricht, but Maastricht-Aachen airport (located some 40 km outside the city centre, in the Netherlands) is connected to only a limited number of international destinations and served by budget carriers. There's an Airport Express shuttle which runs regularly to and from the main Aachen bus station. It's called Gilbacher AirportXpress and leaves from platform 4 . Tickets can only be purchased from the driver and cost € 10,-. There are no trains between Aachen and the airport.
The nearest large airports are Düsseldorf  and Cologne-Bonn . Both airports can be reached by train, via the Düsseldorf and Cologne central stations respectively. Other small airports withing reasonable distance are Weeze (NRN, trains) and Brussels South Charleroi Airport (CRL, trains). Also Liege (Lüttich) airport in Belgium is around 45 min car ride away. Antwerpen airport also in Belgium requires 90 minute car ride. At last, the Eindhoven airport in Netherlands is at 1 hour car ride distance. Probably Aachen is quite unique in terms of having a total of 8 airports in 3 countries within upto 140km reach.
Bus line 50 from Maastricht serves Aachen every 15 minutes and passes through Margraten and Vaals(around 1hour travel time, €5.50 per person after 9 am, €7 per person before 9 am as of January 2014). Bus line 44 runs between Heerlen and Aachen (45 min, €3.95) For €7 you can buy a ticket, which allows all-day travel on South Limburg bus routes, including those to local cities such as Heerlen, and selected train routes. It is 1 h 15 min from Maastricht. See Veolia Transport for timetables (Regio: Limburg). 
For those travelling the other direction to the Netherlands from Aachen the bus stop for the 50 can be found at this location ([Google Maps location])
From Heerlen there's also a direct train connection.
By car, you can just drive in via Vaals or take the highway. The A76 connects to the German A4. Take exit 2 to Aachen/Laurensberg.
The old town is best explored on foot and orientation signs can be found all around. Aachen at a whole is a fairly large city. A car can come in handy but parking can get expensive, especially in the center of town.
Fortunately, Aachen has an excellent city bus system, operated by ASEAG, including a few night bus lines. You can get tickets from the bus driver. You can rent a bike at the "fahrrad station", in the central train station. Although it is not the most biker-friendly town in Germany, there are a number of bike routes and getting around on bike is increasingly popular. Taxis are readily available on the train stations but also on streets.
Opening times of the Cathedral: Jan-Mar: Daily 7AM-6PM, Apr-Dec: Daily 7AM-7PM. Note that during mass access is restricted to attending in the services. Touristic visits are recommended for Mon-Fri morning after 11AM; Sat-Sun morning after 12:30 PM.
Aachen Cathedral is one of the most famous examples of occidental architecture. Around 800, the core building of the Palace Chapel was built. During the 14th and 15th centuries, the Gothic choir (the "Aachen glasshouse"), the north and south chapel were added. Through the centuries, many other constructions and decorations were completed. Today, it is a unique and beautiful two-storey cathedral of classical pillars, bronze railings, golden masterpices, glassworks, etc.
The cathedral is the memorial and funeral place of Charlemagne (+814). During 936-1531, 30 kings and 12 queens were anointed, crowned and enthroned here. In the Middle Ages, it was one of Christendom's most important venues for pilgrimage, together with Jerusalem, Rome and Santiago de Compostela. Heiligtumsfahrt(the Aachen pilgrimage) takes place every year since 1349 (the next one will be in June 2014). In 1978 it was the first German building to be inscribed as a UNESCO World Heritage Site.
The medieval town hall. The mayor of Aachen has his office still in there.
The small dutch town directly next to Aachen. Just take bus number 33 or 25.
The Point where Germany, the Netherlands and Belgium meet. This is the highest Point of the Netherlands. There is a watchtower you can climb. You can get there best if you take the bus to Vaals and take Veolia Transport line 149 or walk.
Uniklinik The university's hospital. One striking example of post-modern architecture like the Centre Pompidou in Paris.
RWTH Aachen If you are interested in architecture, you can find all building styles from 1900 till today concentrated at the city-campus around Templergraben.
Super-C The reception building of the RWTH-Aachen. Build to resemble the letter C. Nicely illuminated at night.
Aachen offers many different cuisines, from traditional German food to exotic cuisines. The centre offers restaurants of all categories, prices being relatively cheap in comparison with other german cities. Students prefer the snack bars and light meals offered at Pontstraße.
Cafe Maredo - Delicious Argentinian food chain based in germany. Good food, not expensive. Located at Blondelstr 11. Open late and offer late-night specials as well as lunch specials.
Estado Steakhaus - Great steakhouse with a salad bar and wide variety of dishes. Estado Steakhaus, is on Seilgraben 39, 52062 Aachen.
Chicken Pont, Very cheap and good Chicken, Pizza and Turkish food, Pontstraße.
Carlos I- This Spanish restaurant offers authentic Spanish cuisine like Tapas, the perfect food for sharing, Paella etc. at medium prices. Located in Rennbahn 1, next to the Cathedral. Changed in another restaurant (Nov 2013)
Polonia, (Marienbongard 24) Polish bistro. Has lunch offers. Four to six different polish beers.
Frietnesse, (Pontstraße) Fries with over 50 different sauces. Also hamburgers and dutch specialities.
San Sheng, (Pontdriesch 13) Authentic Chinese food. Open only during weekday lunch hours.
The Pontstraße begins at Markt facing the historic city hall and ends at the Ponttor, part of the medieval city walls. Pontstraße is the main student hangout and offers a large variety of restaurants and bars, from pizzerias to late night hangout spots and a cinema (Apollo ). A special treat are public fiestas happening at Karneval and important football matches. Don't miss it if you have the chance! Reached by a number of bus lines from Bushof; park near University.
Molkerei - Pub suitable for younger crowd, near Ponttor.
Cafe Madrid - Pub/Bar better for an older crowd, posher, near Ponttor.
Pontgarten - Cheap Cocktails and nice food.
Sowiso / Oceans - Typical student-inn.
Nice pubs elsewhere:
Guinness House - (Neupforte 6) Huge irish pub.
Zuhause - (Sandkaulstraße 109/111) Cozy and friendly bar near the Aachen Ring.
Kiste - (Büchel 36) Small pub. Has a discount on different drinks each day.
Sofitel Aachen Quellenhof, Monheimsallee 52, ☎ (+49)241/91320, . This luxury hotel belongs to the best Aachen has to offer in terms of lodging. Spacious, comfortable rooms (although some could do with a little redecoration), a swimming pool, fitness area and excellent breakfast buffet. The location just outside the historic center is great too.from €130. edit
World War II Henri-Chapelle American Cemetery and Memorial: 16 kilometers (10 miles) from the city near Henri-Chapelle, Belgium. From Aachen, take N3 southwest toward Liege, Belgium. Turn right onto Rue du Mémorial Américain. Open daily except for December 25 and January 1; 9:00 a.m. to 5:00 p.m. The cemetery is the final resting place for the 7,992 American military dead lost during the drive into Germany the Battle of the Bulge. A monument is inscribed with the names of 450 Americans whose remains were never found or identified. A museum and a chapel are located on the grounds. Free.
Dreiländereck- The three-country border of Germany, the Netherlands and Belgium. Just a 10 min drive out of Aachen in the general direction of Vaals (Netherlands). Walk on the soil of three different European countries in just about under a second. Free.
Zülpich is a small town dating from Roman times on the road to Bonn. It has a newly opened museum focusing on Roman baths and bathing culture. It is also a gateway to the Eifel region.
Maastricht in the Netherlands with its beautiful city centre is where the Maastricht Treaty of the European Union was signed in 1992