The Tower of Hurtado de Mendoza is located in Mártioda, which is on the top of a hill that dominated the roads of the 16th century routes that passed close to the Badaya mountain range. Its location opposite the Arrato pass, a natural pass from the Llanada Alavesa to Zuya and, through this valley, to the Biscayan passes, gives it a special strategic value.

At the northern end of the town is the Tower. The current access to the village is from the south and climbs gradually until it reaches the tower, from which, to the north, the terrain descends sharply, forming a veritable wall.

This privileged position, at the highest point, gives the tower an image of great power. Next to the tower is the church, in a lower position and without a bell tower, probably to avoid visual competition. The lords of the tower were patrons of the church.

It is a rectangular tower, with a ratio of almost two to one, which was initially free-standing. It is built with masonry and ashlar at the corners. Its height, about twenty metres, is twice the height of the ten metres of the smaller side, so that if it were not for the palace that surrounds it, its proportions would be incredibly slender. Today it is four storeys high, but the original forging heights had nothing to do with what we see today, as can be seen in the different heights of the medieval openings.

Of the original Gothic openings, the one on the main façade, with a pointed arch and a metre and a half in height, is particularly noteworthy. The two side façades also have Gothic openings, covered, with similar characteristics, but smaller in size. These openings allow us to approximate the construction of the building to the end of the 13th century, being later than the Mendoza tower.

In the wall there are arrow slits distributed around the perimeter, and even the remains of a staircase, originally exterior, which gave access to the first floor of the tower, as was usual in this type of construction. The entrance doorway, located in the middle of the keep, has a pointed arch, 2.40 m high and 1.20 m wide.

The medieval keep was surrounded on three sides by a moat, with a barbican or wall on its edge. The fourth side was the slope of the hill, so there was no need for a defensive moat. According to an account from 1694, the moat had a drawbridge and chains, and was deep and wide open. Today only the moat remains on the south side. It is 4.20 m wide and still has an access bridge, although it is not the original drawbridge. Above it are two modillions of the machicolation that defended the entrance gate to the enclosure, built with a stone arch. The rest of the openings in the defensive wall are 0.55-metre-high arrow slits.

The Hurtados de Mendoza family must not have lived in the tower for long. It is known that in the 16th century they lived in Vitoria, and the tower was in the charge of the mayors. In 1527, the tower served as a prison for the manors over which the Hurtados exercised jurisdiction. In the 17th century it was in ruins, with the roofs collapsed and houses built against the barbican.

In the 18th century, Joaquín María Hurtado de Mendoza, Count of Villafuerte and Marquis of Miraval, gave new life to Mártioda and its tower. He built the palace around the tower, constructing an 18th-century dwelling.

When the palace was given the appearance of a palace, windows were opened, changing all the floor heights. The new windows that were opened on the main body of the tower have large stone jambs.

The south façade, the most open, tries to maintain a symmetry of openings. Seven small windows were opened above the palace buildings. The smallest one, in the highest position, next to the battlements, has a gutter with a strong moulding. The other openings are evenly distributed.

The east and west elevations are only pierced by a central shaft of openings. The north elevation has no openings, except for the primitive upper arrow slits.

The body of the new palace functions as a plinth attached to the tower. There is no clear hierarchy of openings. The main additions are on the east and west, with the south side protecting the entrance and the north side serving as a corridor linking the two wings. The height of these additions is ground floor and one storey.

On the south, protecting the original entrance to the tower, a projecting body stands out, which houses the door and two windows, but is reminiscent of a large machicolation. There is a second access door, on the same façade, to the east, covered in sheet metal, with the inscription: "ME YZO JOSE DE LEIZA. YEAR 1799".

There are further additions to the west, around a second square courtyard. These constructions seem to have been built for agricultural use rather than to represent the palace.