~ Bahía de Banderas ~

The Bay of Flags plunges to around 1800m (5900ft), has 160km (100mi) of sensational shoreline and comfortably makes it into the list of the 10 biggest bays in the world (it's number seven).  Ostensibly the submerged crater of a long-extinguished volcano, Bahía de Banderas is an environmental wonderland populated by giant manta rays, dolphins and (during their birthing season from November through March) humpback whales.  It's also inhabited by activity-crazy humans, occupying themselves by diving, fishing, water skiing and generally enjoying themselves in and around the bay's waters.

~ Beaches of Puerto Vallarta ~

Though downtown Puerto Vallarta has its attractions, this resort's prime raison d'être is the white sandy stuff sprinkled along the edges of the adjacent Bahía de Banderas.  The beautiful local beaches begin in town, south of the Río Cuale, in the guise of the towel-swept Playa Olas Atlas ('Beach of the Big Waves', though to be honest there's nary a big wave to be seen here) and next door at Playa de los Muertos ('Beach of the Dead', a name which apparently harks back to some long-forgotten seaside battle).

Downtown ~ Puerto Vallarta, Mexico:

Though Puerto Vallarta is now dominated by its modernistic, resort-stacked beaches, there are enough of the old red-roofed adobe houses lining the streets and cobblestones underfoot to keep alive the spirit of a once-charming seaside village.  To get a sense of the more-established parts of the centre, stroll a block east of the pedestrian-tramped Plaza Principal to the towering facade of the city's landmark cathedral, Templo de Guadalupe, built in 1951 and adorned with the replica of a crown worn by an 18th-century Mexican empress.  Backtrack across the square to the arches of the outdoor amphitheatre on the bay.

Meandering its way north from the amphitheatre is the Malecón, a long seaside walkway adorned with a larger-than-life seahorse statue, a plethora of drinking dens, and plenty of places catering to la comida (the main meal of the day - taken in the early afternoon) and la cena (the typically lighter evening meal).  There are several Cuban cigar bars on this strip for after dinner.

Wedged into the mouth of the Río Cuale, the slender river that divides the city into its distinctive northern and southern swathes, is the 2ha (5ac) Isla Cuale.  This diminutive island is littered with restaurants and shops, the latter mostly specialising in clothes and local arts - for some good deals on Mexico's outstanding range of artesanías (handicrafts), cross over to the north bank of the Río Cuale where you'll find the 150-stall market called Mercado Municipal.  At the island's western, Pacific-viewing end is a tiny, lush botanical garden and the equally tiny Museo del Cuale, which features a collection of pre-Hispanic archaeological artefacts from tombs cracked open throughout Jalisco state, as well as in the neighbouring states of Colima and Nayarit.