Alicante is otherworldly, if you know where to look
Of all Spain's mainland provincial capitals, Alicante (Valenciano: Alacant) is a dynamic, attractive Spanish city with a castle, old quarter and long waterfront. The eating scene is exciting and the nightlife is absolutely legendary, whether you're chugging pints with the stag parties at 7pm or twirling on the dance floor with the locals seven hours later. On a weekend night it's impossibly busy and buzzy year-round.

Castillo de Santa Bárbara
There are sweeping views over the city from the ramparts of this large 16th-century castle, which houses a museum recounting the history of the city and contains a couple of chambers with temporary exhibitions. It’s a sweaty walk up the hill to the castle, but there’s a lift that rises through the bowels of the mountain to the summit. To return, it’s a pleasant stroll down through Parque de la Ereta.

Mercado Central
Alicante's main market hall is a feast for the eyes and other senses. Dating from the 1920s, it has a few Modernista flourishes; it suffered extensive damage from bombing in the civil war.

Museo Volvo Ocean Race
On the pier, this museum brings to life the gruelling conditions of the round-the-world Volvo Ocean Race with a simulator, videos, photos and a display of the gear taken on-board. One of the participating yachts is also here for you to have a look at: fancy jumping aboard for 10 months?

Playa del Postiguet
Immediately northeast of the port is the attractively coloured sandy beach of Playa del Postiguet, Alicante's city beach. It gets packed in summer.

Lucentum
The ruins of the Roman town of Lucentum, a forerunner of Alicante, lie about 3km east of the centre in the locale of Tossal de Manises. Excavations have revealed a rich wealth of pottery. You can make out clearly defined streets as well as bathhouses, the forum, a large house with columned courtyard and various other dwellings. Bus 9 or 21 will get you here, or you could jump on the coastal tram.
Source:lonelyplanet.com