Seville gives you plenty to see. The Giralda, the cathedral beside it, the tilework of the Real Alcázar, the narrow lanes of the Santa Cruz quarter. Plenty of people come for that alone.

For a few weeks every year there is as much to smell as there is to see. Step outside on a morning in late February and the air is full of azahar, the blossom of the bitter orange tree. The word comes from the Arabic for flower, and the same root gave Spanish its word for luck. It is sweet and a little bitter, and it is everywhere.

It comes from the trees. Seville has more orange trees than any city on earth, upwards of thirty thousand of them. They line the streets, fill the plazas, and stand in the patios of houses and churches. There is a courtyard of them inside the cathedral walls, the Patio de los Naranjos, and more fill the Parque de María Luisa. Most of the year they are just street trees.

Santa Cruz is where you feel it most. The old Jewish quarter was built with its lanes deliberately narrow, for shade and cool air, and the same tight streets hold the scent close. Sit in the Plaza de Doña Elvira, a small square with a fountain and tiled benches under the orange trees. Or take a table on Calle Mateos Gago, where the terraces run under the trees with the Giralda straight ahead.

The Moors brought the tree from Asia and planted it across the city in the ninth century, and it has been here ever since. The fruit is no good to eat. Seville oranges are bitter, and most of the crop goes to Britain for marmalade. The trees were kept for shade and for the blossom, and the people who live here get both every spring.

When the city prunes the trees, the cut branches send the scent back into streets that already carry it.

If the blossom is what you want, come from late February into March. It peaks in March and fades by April. This is also Semana Santa, and a few weeks later the Feria de Abril, so book early.

Then give it time. Walk in the morning before the streets are busy, and find a bench in one of the smaller squares.