Undeterred by such nagging issues as the economy and unemployment -- both in a highly precarious state at the time of writing -- Madrid's communication and ecological improvements continue to expand under the relentless guiding hand of Mayor Alberto Ruiz-Gallardón. His dream is to see the still-in-progress 14km/9 mile-long Madrid Rio development transform the Manzanares River in its section from the Puente de Toledo to the Parque del Oeste into a whole new airy green zone, light years away in mood from the claustrophobically narrow-laned old center. Most of its 811 hectares (just over 2,000 acres) have already been laid out with trees, flower-filled gardens, and lawns, though full completion is not expected until 2012. Additional small sandy "beaches," complete with adjoining solariums and sports centers, are also planned. (For more information on this, including a 5-min. video with English-language narration, check out www.munimadrid.es/madridrio).

The latest stage in metro travel, the tren ligero (a smaller streamlined TALGO-shaped tram, similar to those also facilitating commuters in Bilbao, Valencia, and Barcelona) has for the past few years been providing services to classy northerly suburbs such as Boadilla del Monte, Pozuelo de Alarcón, and Aravaca, while cercanías (suburban rail services) speed residents of other outlying satellite towns, such as San Sebastian de los Reyes and Colmenar Viejo, to Madrid's center in less than half an hour.

Expanded and renovated rail and bus stations, from the large main Atocha and Chamartín termini to the smaller Príncipe Pío and Moncloa stops, all function in ecologically friendly, well-ventilated underground locations. Public transport throughout the city is economical and efficient, with metro services extending as far as the airport; and the ubiquitous tunnels of pedestrian and subway underpasses, together with a widening of countless streets and avenues, have all improved road access into and around the city. The expanded Barajas airport -- undaunted by the ETA terrorist bombings of its terminal 4 car park in December 2006 -- continues to develop its facilities and number of international flights and is now the third busiest in Europe.

The most visible symbol of all this progress is a brand new quartet of Spain's highest buildings, known in Spanglish as the Cuatro Torres Business Area (CTBA). The buildings stand on the site of the former Real Madrid sports grounds, just north of the twin sloping KIO glass and concrete office towers, which previously dominated Plaza Castilla and formed a kind of jet-age gateway to Madrid. Three of these soaring new concrete and glass icons, named Cristal, Espacio, and Sacyr Vallehermoso, were completed in 2008; the fourth, Caja Madrid -- designed by the ubiquitous British architect Norman Foster and the highest of the four at 250m (750 ft.) -- was finished in 2009. Collectively, they're an emphatic in-your-face reflection of capitalist wealth. Not so impressive is the news that (at the time of writing) two of them are still empty, having so far priced themselves out of the current market.

The city's increasingly mixed population is starting to rival those of London, Paris, and Berlin to an extent unthinkable just a couple of decades ago. For decades, Madrid was the most purely national and homogenous of European capitals, and foreign residents were a relative rarity -- high-paid executives working in international businesses along the Castellana aside -- who totaled barely 1%. Today's resident immigrants come mainly from Africa, South America, the Hispanic Caribbean islands, and Eastern Europe. Ecuadorians and Romanians tend to predominate. Latin Americans, for whom the language obviously presents no problems (Portuguese-speaking Brazilians aside), have opened large numbers of cafes, shops -- especially bakeries -- and locutorios (long-distance phone call centers). Meanwhile, the Russians, Poles, and Czechs who work on many of the eternally busy building sites and in practical fields such as plumbing and carpentry have shown great versatility in their work and in picking up Spanish.

The most rapid change in recent years, though, has been the growth of the Chinese population, which has now created a small world of its own in the southwesterly former working class suburb of Usera. Though this Lilliputian Chinatown pales in comparison with those of New York and San Francisco, it's burgeoning so fast in this ever-changing metropolis that it could soon approach them in stature.

Madrid is now officially one of the "greenest" cities in Europe, with verdant areas springing up every year thanks to its environmentally aware town hall. Traditionally the Retiro, where Madrileños over the past decades have relaxed amid the endless array of trees, flowers, and fountains, and the huge Casa de Campo moorland, with its copses and bird life, are the city's twin lungs, aided by the regular flow of pure mountain air from the Guadarramas, 97km (60 miles) away. Additionally, in the past few years, hundreds of thousands of trees have been planted in green zones in and around the city, intersected by walking and cycling lanes that now total nearly 100km (62 miles) and completely encompass the outer city. The above-mentioned Manzanares River development -- with the adjoining M-30 highway running underground -- now has newly pedestrianized and flower-filled parkland adjoining Casa de Campo. And several buses are in service using environmentally friendly fuel.

In spite of all these dramatic social, technological, and ecological changes, at the city's heart remain the old traditional Los Austrias, Plaza Mayor, and Royal Palace, still exuding their timeless atmosphere, and ringed in turn by regenerated Castizo (traditional) districts such as Chueca, Malasaña, and Lavapiés. These districts have remained unchanged architecturally for centuries, but offer a vibrant, stimulating blend of the bohemian and ethnically diverse, thanks to a resident bevy of artists and fresh influx of arrivals from other countries.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.