La Sagrada Familia inspires awe by its sheer verticality. [Liu Lu/China Daily]

Work on the cathedral began 133 years ago, yet it is still incomplete, although the current intention is to have it finished by 2026, the centenary of Gaudi's death. However, even in its unfinished state it is a sight to behold with its eight mystical-looking steeples that could be taken straight from the pages of a fairy tale.

The interior offers sights that are just as breathtaking. As soon as you get inside you will find you are walking into a place that looks other-worldly, and the design of the interior is just as intricate as that of the exterior.

Something to be on the lookout for is the way light penetrates and illuminates the cathedral, particularly early in the morning or late in the afternoon.

To avoid waiting in a line to buy tickets, you are well advised to book in advance online.

Gaudi's architectural wonders, including Casa Batllo, La Pedrera and Palau Guell can be found in various parts of Barcelona. If your time is limited, pick at least one or two of them.

My favorite is Casa Batllo, in the city center, Its radical design was heavily criticized when building was completed in 1906 but today is widely regarded as one of the best of Gaudi's many masterpieces.

With wild colors, mosaic tiles and unusually shaped curves and arches, Casa Batllo looks as if it is the realization of a creative genius' fantasy, in sharp contrast to the mundane look of neighboring buildings.

On a gloomy rainy day the stained-glass windows and the ceramic tiles brighten up the interior, and the terrace and roof offer panoramic views of the city.

While in Barcelona you could also do worse than seeing a few museums, one being the Picasso Museum. Even if none of the artist's most famous works are housed here, its collection of lesser-known works can be described as unique.

You can visit Barcelona any time of the year, although summer, when the city's beach attractions really shine, is by far the most popular time.